Fire and heat cause many deaths, and a far greater number of injuries. In fact, burns are incredibly common, and frequently lethal. Large thermal burns are some of the worst injuries one can receive. Children are particularly likely to receive thermal injuries because they are active, and "get into things" before they're old enough to know what poses a threat. Serious damage to the skin is equivalent to putting a large hole in our outer protective covering. When we do this, things in the outside world, particularly agents of infection, have an opportunity to get inside our bodies, and make things still worse.
There are several common types of burns, including:
This review will concentrate mainly on burns due to heat from outside the body. Such thermal injury only occurs when the amount of heat delivered to the skin exceeds the amount that can be removed by the body. Obviously then, the rate of delivery is often more important than the total amount. We know from experience that boiling water delivers heat to our skin much faster than an electric blanket. In scalds, burns due to hot liquids, the heat inherent to the fluid itself (the specific heat) is a major factor. Water, which is so common, happens to have a high specific heat. Although water does not usually exceed about 212°F (100°C) at sea level, other liquids, such as oils and molten metals, can reach far higher temperatures at normal atmospheric pressures.
The duration of exposure or contact with the skin is also a major factor, so we start to see how clothing may affect the outcome if it holds hot liquids in contact with the skin, when otherwise they would have run off. Likewise melted metal may solidify as it starts to cool, and because it remains in one place, continues to deliver heat to a given area of skin. There are many variables.
Unfortunately, in this day and age, it is not safe to assume that all thermal injuries are accidental. In fact they must be evaluated with many other possibilities in mind, including arson, insurance fraud, drug abuse, child abuse, domestic violence, elder abuse, and even suicide, or attempted homicide.
The situation is somewhat reminiscent of a story about two pathologists, taking a look at the body of an attractive young woman laid out for examination in their autopsy room. The younger comments upon the abrasions and bruises on the neck, whereas the old-hand, who is nearing retirement, calls for a sexual assault kit.
In other words, there may be a great deal more to a fire, and associated thermal injuries, than first meets the eye.
To get a feel for the problem, let's consider the figures for unintentional residential structure fires in the United States during 1999, and break them down:
|Per year||Per day||One every||Trend|
|Residential fires||337,300||924||1 minute 33 seconds||Down|
|Residential fire injuries||14,550||40||36 minutes 7 seconds||Down|
|Residential fire deaths||2,390||6.5||3 hours 40 minutes||Down|
Cooking equipment accounted for 29% of the fires, 28% of the injuries, and 13% of the deaths. Heating and cooling accounted for 13% of the fires, 9% of the injuries and 13% of the deaths. Electric wires and fixtures accounted for 12% of the fires, 7% of the injuries and 6% of the deaths.
As we might expect, the items first ignited were upholstered furniture, followed by mattresses and bedding. Smoking materials were still responsible for roughly 23% of the deaths.
Fire-related injuries and deaths also have enormous indirect costs, such as lost productivity, and medical care.
The losses due to accidental fires, arson fires, and fraudulent claims are widely perceived, but the numbers are bigger than many expect. Here are a few estimates from The National Fire Protection Association (NFPA), also for 1999:
To make matters worse, it was reported that the arrest rate for arson cases in 2001 was only 16% nationwide.
It's amazing how many insurance companies employ:
and yet these companies continue to payout on the basis of poorly conducted autopsies, poorly worded autopsy reports, and seldom consult anyone who has experience in the medical aspects of death investigation.
Costly litigation is associated with both property and human losses, and further compounds the problem.
Fire not only injures survivors, but it often makes the bodies of victims hard to identify. Evaluation of a burned body is often quite difficult, and there are many potential mistakes and sources of error for the uninformed.
Arson means to start a fire, or cause an explosion, with the purpose of:
Arson clauses in property insurance void coverage if the fire is set by the insured, just as suicide clauses commonly void coverage for suicide within two years of taking out life insurance (see below).
In 1997, a total of 81,753 cases of arson were reported (an average of 224 a day, or one every 6 minutes 26 seconds), but some people estimate and believe that roughly six times as many cases go undetected or unreported.
There are several common categories or types of arson (deliberate fire setting):
Unless arson is obvious (e.g. trails of paper throughout parts of a building, gasoline cans, and more than one origin, with other evidence of crime) it is necessary to show that fire was not due to something else.
Make a point of looking up the proper meaning of the basic fire terms in a book on fire and arson. They have very specific meanings for those who work in the field. We need to communicate accurately with fire fighters and fire investigators, and they have their words and specialized terms, just as we have ours.
When you start learning you will soon find that misinformation is being perpetuated, just as it is in other fields. Examples include:
1) Years ago, people were taught that if a fire spread beyond the room of origin within 20 minutes then it must have been aided by an accelerant. It may have been true then, but it's not true today because of the changes in available fuel. Many modern furnishings yield far more heat than the leather, cotton and wool of days gone by.
Flashover (everything in a given room or compartment burning) always existed, but now it's often closer to 5 minutes from the first open flame, and 2-4 minutes from the time a smoke alarm first sounds. Several years ago a survey found that people expect 10-15 minutes evacuation time, when in reality it's usually far less. A house fire can double in size every 30 seconds or so.
2) Spalling of concrete does not necessarily mean that an accelerant was poured onto a floor. Spalling occurs even when fire has other origins, because there's a relationship to the shock of sudden cooling by water. Furthermore, recent research indicates that some high strength concretes may flake off (focally "explode") in areas subjected to heat, because their greater density and relative impermeability makes it harder for steam to escape.
3) In the past people claimed to be able to relate time and/or temperature to the depth of charring of wood. However, in some modern structures, wood might have been treated with fire retardant which significantly reduces the rate of penetration, so a little caution goes a long way. Engineered lumber is also increasingly common (for example, gluelam beams, laminated strand lumber (LSL), laminated veneer lumber (LVL), oriented strand board (OS8), parallel strand lumber (PSL), I-beams, open-web joists, finger jointed studs, and other manufactured lumber products.)
If like me, you're seeking the most basic of facts to serve as a starting point for observations, remember that when soft woods are exposed to heat, charring occurs and the surface layer then acts as an insulator. The best guide I can cite is that, if soft wood, such as is used in glue- laminated beams, is exposed to a fire, it will be damaged/penetrated at about 1/40th inch per minute. Of course it's uneven, being deeper at corners that on the sides, but at least it's some sort of guide.
We also need to review or learn what fire is. The three essentials are fuel, oxygen and heat.
Hydrocarbon fuel + oxygen -7 carbon dioxide + water + energy as heat and light. An initial input of heat, perhaps from a match, converts some of the fuel into a form (gas or smoke) that can mix with oxygen in the air and start to burn. The heat produces more gas and smoke, so the process keeps going. The region that contains enough heat to maintain the process, constitutes and defines what we see and know of as flame. Although gas and smoke contain many chemical compounds, the underlying reaction is:
There is marked regional variability in the quality of death investigation in the United States, from about the best in the world, to some of the worst.
Don't judge a local death investigation system by its name. It may be a Coroner, Medical Examiner, Sheriff-Coroner, Medical Investigator, or Justice of the Peace system. Instead, judge a system by the personnel, its performance, the level of support, and the overall set-up. Is it politically or scientifically oriented and directed? An interested lay coroner often does a better job than some physician who ran for political office and doesn't care much about anything except looking important.
Do not assume that the pathologists you work with have received proper training in medicolegal matters. Too often they haven't. There are various specialties within medicine, just as there are in law and engineering. Knowing about hospital pathology (tumors and the chemistry lab) does not fully prepare them for medicolegal work without additional training, any more than being a physician qualifies me to do brain surgery without additional training. I have no idea why this simple concept is so frequently overlooked.
At present, there are many problems facing the specialty of forensic pathology (including declining budgets, low pay, employment by state and local government, shortage of trained people, and AIDS, etc.) so the situation is not likely to improve any time soon. However there are encouraging signs, suggesting that local awareness and standards may be on the way up.
When someone dies, the Medical Examiner or Coroner has to determine two very distinct things:
It is essential to know and understand the definitions of cause and manner if one is involved in any kind of death investigation.
CAUSE of death is:
If death occurs within seconds or minutes, say after a few thousand gallons of gasoline caught fire, just about everyone will understand that heat and burns are the cause of death. However, if death should be delayed, when for instance someone is burned by lighter fluid, subsequently develops an infection and dies a few weeks later of septic shock or organ failure, it is not unusual for people to lose sight of the initiating or proximate cause (the burns) and somehow see and regard the death as due to infection. In other words, they fail to see that the burns were the initiating event, and that without them the infection, and eventually the death, would not have occurred.
If they fail to see this obvious interconnection, the death will be seen as natural, the case may not be reported to the Medical Examiner or Coroner as it should be, and a death certificate may be improperly issued, listing kidney failure, due to low blood pressure, due to septic infection, as the sequence leading to death, but never taking the thought process back to the burns that initiated the sequence of events ending in death.
MANNER of death is:
In the United States we have five options (Natural, Accident, Homicide, Suicide, Undetermined), Anyone of the five can apply in a fire-related situation.
Proper determination of the manner of death is extremely important when it comes to insurance settlements. For instance:
After a fire, a person may be found dead or may die shortly thereafter, but the manner of death could be anyone of the five. As a whole, the manner of death will usually turn out to be:
Following are five simplified scenarios to make the idea clear:Natural:
The above are simple examples. There are far more difficult cases, but most of the time manner of death is fairly straightforward, if the scene and the death are properly/thoroughly investigated.
Note that even more manners of death are used in other countries. For instance "misadventure" and "open verdict" in the UK (which are variants of accident and undetermined).
So when we're confronted by a fire-related death, we have to decide if death was due to, a direct outcome, of the fire, or if death took place in a fire-related situation.
Mechanism of death is useful to know about, but it's far less important than cause and manner.
MECHANISM of death is:
For instance, the heart or lungs may stop, or as so many say, they arrest.
Clearly, if the mechanism is initiated by the cause, it must be different from the cause. There are two easy clues to recognizing mechanisms, which are that (a) when you look at them you can't tell what initiated them, and (b) all of us will have them about the time that we die! For instance, I am certain that my heart will arrest sooner or later, but what interests me is what will cause it to do so!
Mechanisms of death include: cardiac arrest, respiratory arrest, cardiorespiratory arrest, and so forth. Everyone's heart comes to a stop sooner or later, but saying that it did so doesn't tell us why (the cause of death), which is what we all want to know. There's lots of reasons for the heart or lungs to stop, all the way from being crushed by a truck, to being shot in the head, or developing cancer.
Lots of people, including many physicians, fail to distinguish mechanism from cause. You will become aware of this when a person dies after 90% of his total body surface area was burned. The autopsy is just under way when someone calls from the hospital to ask why the victim died. If you reply that he died of his burns, they will again ask why he died, making it clear that they are thinking about the immediate cause or a mechanism, to explain some observation during the last few hours or days of his life. It usually makes little difference if the lungs or kidneys failed at the last, so long as failure of either was initiated by burns. Thermal burns represent the cause, the initiating event, without which death would not have occurred.
Simple observation at the scene of a fire can, on occasion, be far more important than the autopsy. Usually you will go through a 3-step diagnostic process just as with living persons.LIVING
A few simple numbers (United States) to get started:
It's impossible to list all the ways in which fires and and/or burns arise. However it's important to think in terms of general injury and event patterns, so following are a few guides according to age and behavior:Small children:
These lists could be greatly expanded, but what is likely to happen depends upon age.
If there has been a fire in a building, particularly in a residence, it's a good idea to proceed on the basis that there might be human remains in the debris, until it becomes clear that there aren't. If remains are found, the first step is to decide if they are animal or human.
If the remains are found to be human then the BASIC QUESTIONS are:
Lesser, but relatively important, questions arise from time to time. For instance, federal and state laws provide for collection of taxes after death, but less obvious issues are seldom considered. For instance, if a veteran and his wife should die in a fire, is she still eligible for VA burial benefits? Perhaps so, but it won't be long before someone's wants to know who died first?
Double and triple indemnity insurance is important to family members. These policies pay the face value for natural death, but double or triple the amount for accidental death. Some won't pay for suicide at any time, while others won't pay within a specified period (e.g. 2 years) after taking out the policy.
Fires are often set to conceal homicide, suicide, or obscure identity, and to try to cover up other criminal activities such as theft or searching for drugs and valuables. Never assume (ASS-U-ME) that all fire related deaths are accidental, because many are not.
What should you note during the autopsy on a fire or burn victim? The simple answer is that you should try to note everything you would normally note during an autopsy examination, less those items that have been obscured or altered by fire. Then make additional notes on how the fire affected the body.
For instance, if time of death should be an issue, and if the body was heated for a while to an unknown degree in a fire, you obviously cannot rely on body temperature! Likewise you can't answer questions about temperature after a body has been cooled. Don't laugh, I've seen and photographed a body packed in a bag of ice, accompanied by a note stating the local temperature that day, and asking questions about the time of death!
I will assume that there are no "complications" such as hazardous chemicals or nuclear radiation to disturb or delay our routine. I will therefore proceed on the basis that we have a dead body, that was found after a fire was suppressed, or a burned living person to examine.
This is a classic mistake.
"There is no body so badly burned, or decomposed, that it does not deserve an autopsy". (Charles P. Larson, M.D., Tacoma, WA. - deceased.)
A steak may be charred on the outside, but the inner parts, especially if the meat is thick, may still be edible after we have cut the overcooked outer portions away. Likewise in the case of bodies, the outside can be blackened and parts of the limbs completely destroyed, while the inner parts remain comparatively well preserved, frequently allowing us ample opportunity to:
Teeth are relatively hard to destroy and are particularly valuable in making identification, provided we have an idea who the dead person(s) might be, and can make contact with any dentist who provided treatment during life. This is because there are 32 adult teeth, each of which have five surfaces (biting, inside, outside, back and front). Thus, the mathematical odds of any two people having the same combination of absent teeth, and restorations of various kinds, involving the 160 different tooth surfaces is extremely small. Even the shape of the roots can establish identity.
Note that the examination should be as complete as it can be in the circumstances. Obviously you cannot examine a forearm and hand if the limb is missing below elbow level, but never make the serious mistake of doing a "partial autopsy". Partial means other than total or whole, and thus incomplete. For example, failing to open the head, to look for brain damage.
This is like steak shrinking as it is cooked. There are several variations and possibilities for error:
The combination of heating, drying and loss of water often causes skin to shrink.
This leads to several possible errors:
A reverse variant of facial change is the marked swelling of the face that may occur in a person who lives for a while after a significant burn. This can interfere with recognition and identification of the victim.
Bone shrinks if it is heated in just the right way. Like most things, bone expands slightly to begin with but then, as the heat takes effect on the various components, it shrinks. Significant shrinkage has been reported, but the percentages vary. It can be more in some bones than others, and it's only recently that I've heard of a worthwhile paper on the subject. A small amount of shrinkage is reasonable in house fires. In the meanwhile, so long as you're aware that calculations of size or stature may be in error unless some allowance is made for shrinkage when heat is applied, all will be well.
Note that shrinkage in length results in an even greater reduction in area, because of simple cross sectional mathematics. (An imaginary square of bone which originally measured 1 x 1 inch, might only shrink 3% each way after heating, Thus is will measure 0.97 x 0.97, which is only 0.941 of its original area). This can lead to errors when counting the fine bone structures per unit area, (osteones), unless the two dimensional size (area) change is factored in.
This commonly occurs following:
In the absence of heat, skin blistering and slippage may also be seen in association with:
Thus there is potential for misinterpretation. Blisters are not always due to heat or to steam.
Sometimes, enough heat passes inwards through the body wall to, in effect, begin to cook portions of the tissues immediately beneath. For instance, if the chest wall is well heated, but not sufficiently to burn it through, more than enough heat can reach the front of the heart to cause a change of color (often a slightly variegated yellowish pallor) and some focal shrinkage.
There have been cases in which these simple changes have been mistaken, by the unaware and untrained, for shortage of blood supply to the heart muscle (heart attack, myocardial infarction) and for abnormally small (coronary) vessels on the surface of the heart. In fact the color and shrinkage were due to the ingress of heat.
Likewise a whitening and opacification of the corneal areas, in front of the iris of each eye, can lead to faulty estimates of eye color. The change is akin to cooking white of egg, which goes from clear to opaque white, when the protein is denatured by heat.
There is a natural tendency to use hair style and color for recognition and identification of deceased persons. Potential problems include:
I have seen this many times but have yet to perform my own tests to confirm the temperatures at which it occur. However it's fairly clear that it doesn't take a great deal of heat, perhaps 1 to 3 times that of boiling water, or thereabouts.
Regardless of the exact temperatures, heat usually causes hair to change color to brassy or slightly reddish hue. Such alterations of color may be sufficient for misidentification, because it is relatively common to ask friends and next-of-kin to make identification at the very time when they are upset. Furthermore most relatives are not accustomed to seeing bodies of any kind, let alone victims of fire.
It is particularly bad if a person viewing the remains should decide that the body is not that of the friend or relative, when in fact it is, thereby delaying identification, and later tarnishing the image of the investigating personnel and their agency.
A few synthetic fibers change color when heated. It is uncommon, but I have seen blue denim jeans turn a bright red, apparently when acrylic fibers reached about 180°C. Again there is potential for misidentification.
This results from actual physical destruction of parts of the skin, the outer (distal) parts of the limbs, and from evaporation of fluids. It is far from unusual for an adult body to be reduced to half the living weight, or less. Those who are unfamiliar with such losses may decide that the 200 pound man who is missing simply could not have been reduced to the 120 pounds of remains being examined. In fact even greater reductions in weight may occur if the conditions are right, so weight can be very misleading. Reduction in weight may also contribute to mistaken identity.
An adult body will not usually be totally destroyed by fire. Remember how hard it was to dispose of bodies in the WW2 concentration camps. Of course in a prolonged extremely hot, oil refinery or intense chemical fires, even an adult can be completely destroyed.
The bodies of children and animals are sometimes completely destroyed, but it isn't particularly common. It is estimated that about 56% of US households have dogs or cats, and about 35% have children, so it pays to look for remains that are far smaller than adults. (See #24 below). In general, of course, the harder and more thoroughly you look, the more you are likely to find.
Heating and drying (combined with muscle contraction) can lead to bending of the body, with resultant shortening and under-estimation of stature. This results, in part, from measuring a body when it isn't lying straight, but slightly bent at one or more joints. Add focal loss of tissue thickness (e.g. of the scalp), and the result, yet again, can be mistaken identity.
Even the natural healing processes can look peculiar to those who haven't seen them before, or if the pathologist who's performing the autopsy is in a hurry on not inclined to explain.
Very occasionally deaths will result from the untoward consequences of treatment, especially in children who are treated at home for burns when they should have been taken to a hospital. Substances intended for use on small burns have been known to get into the system through larger ones, and can be toxic when used improperly (to excess).
If the body surface is sufficiently intact to permit detailed visual examination there is relatively little need to x-ray it. However, if the body surface is even slightly difficult to examine, be sure to take a complete set of x-rays, or request that the body be run under a fluoroscope. A little soot can be wiped away, but as soon as there is significant burning it is all too easy to overlook features such as bullet wounds.
X-rays will help in several ways:
Note that x-rays of the teeth and jaws for identification purposes are best taken by a method as close as possible to that used during life, to minimize perspective distortion.
In small towns and rural areas, it is not uncommon to encounter a situation where the Coroner does not have, or does not contract for, proper access to x-rays. After all, the local hospital administrator isn't likely to be particularly keen on the Coroner hauling bags full of dirty, smelly, victims through his nice, clean premises! So if you are allowed in, be sure to learn the little tricks and tips that make you seem cooperative, and therefore more likely to be invited back, such as keeping the x-ray cassettes clean by putting them inside one or more plastic garbage bags before they are placed under the remains, and by doing most or all of the body hauling and lifting.
Failing this don't overlook the local veterinarian who often has a portable x-ray machine. He, or she, may well be accustomed to x-raying a variety of smelly goats and sick cows, and may get quite a kick out of helping you with a burned or decomposed body! I have found them to be an enormous help and ally on several occasions.
Eyewitness reports of screams for help, and of banging on the inside of locked doors and windows may be received, but even if you do receive such reports, be sure to continue to look for:
It may be possible to find soot in the airways days after injury. Suppose, for instance that an elderly man is in a nursing home when a fire breaks out in a nearby room. If he develops pneumonia and dies a few days later, finding microscopic amounts of soot in his lungs will almost certainly mean that his death was directly related to the fire, provided his lungs were not giving problems prior to the fire.
Note that red edges surrounding heated zones of skin do not necessarily mean the person was alive. This is a contentious subject, and a variety of opinions may be expressed, but put it this way. Suppose you had just died of some other cause, and then a part of your skin was heated, where would the blood go as the skin shrank, if not to the edges of the heated/contracting/ coagulating area?
Photographs and diagrams are desirable. Such documentation may enable an appreciation of how the injury occurred, leading to a determination of cause, and thence to the manner of death. For instance:
Fire scene photography.
I won't go into detail, only make a few general points, and leave it at that. Obviously the scene of a fire should be photographed much like a crime scene. The fire may have been set, so take your photographs in a logical"walk-up" sequence, distant, medium and close-up. Take the various stages, if you are present, from suppression to overhaul. Your photographs should tell a story from the time you arrive until you depart. Don't just think of the fire by itself. If there is no service drop to the building, the fire is probably not due to an electrical fault. Is the gas turned on at the meter? What are the weather conditions? Are there any signs of forced entry, other than by the fire department?
Any photographic or video record is better than none.
A thoughtful photographer, with an average camera will end up with more useful pictures than an uncaring person with an outfit costing many thousands of dollars. High-tech modern systems can calculate apertures and shutter speeds, but they cannot decide what pictures to take.
Most of the basic rules of photography apply.
Since the size of the light sensing chip in most digital cameras is smaller than a frame of 35 mm film there is likely to be a lack of angular coverage. It's much like taking a 4 x 6 inch print and cutting a strip about o/.-inch wide from each of the long sides and 1-inch from both ends with a pair of scissors. You'd still have a picture, but you wouldn't see as much of the scene as before. so, make sure that any digital camera you're thinking of buying has enough angular coverage for your applications.
Most cameras are designed for the average (meaning amateur) user in average conditions.
You are not an average user, nor in average conditions, when you take a camera into a fire scene. The subject matter is likely to be smoky, darkened, or verging on black. You will probably have to make exposure adjustments (deliberately increase the amount of light reaching the film or the chip) even if you are using automatically controlled flash lighting. Automatic settings are based on the assumption that an average amount of light will be reflected from nearby walls and ceilings, but this will not be the case if you are in a blackened room, or a space that's larger than average due to the collapse or overhaul of non weight bearing walls, or sliding partitions. You may have to select setting for a more distant range (for instance by setting the 16-32 foot range on the system, even though you may be working at 8-16 feet). It will depend on the type of equipment. If you're dOing any significant amount of fire scene photography and still using film, I suggest that you set your flash controls to manual, and run a few tests at various distances with the commonest subjects. That way, if you're in doubt, you'll have a proven exposure to use, that will ensure some good pictures.
The color of smoke is important in a fire investigation, and should be recorded when possible, sometimes at more than one stage. However, the color will appear different according to the angle from which it is illuminated by the sun. You can see the same effect on stormy days by comparing clouds that are between you and the sun, with others that are illuminated by the sun when it's behind you. You may have to take several photos of the smoke, or make significant allowance for the ambient lighting, if any useful information is to be derived from your photographs. The color of flames may also be important, but since these emit their own light, they are less subject to changes brought about by ambient lighting, but proper exposure becomes quite important.
When flash units are used close-up with non-automatic cameras, they tend to give under exposure, the very thing you don't need when the subject matter is already sooty and dark.
Bare bulb flash can be a useful tool to get better illumination of blackened interiors.
Holding the light source above the lens or off to one side (some distance away from the camera lens), can help to produce better pictures if the atmosphere is still smoky or steaming. This is because there will be less back-scatter of light from traces of smoke or from steam, into the camera lens.
If taking photographs of an unknown victim, never hold the lens closer than about 4 or 5 feet from the face. If you get too near, the cheeks will obscure the ears, because light travels in straight lines, and you will have trouble comparing your photographs to others taken from a longer distance during life.
Carry several rulers with you for use as scales of size. These should be free of all advertising and ideally you should have two or three, especially one gray and one black. If you put a dark ruler next to a dark object you will be able to adjust the overall exposure for a reasonable result. But put a white ruler next to a black subject and the white ruler will "burn out", meaning become seriously overexposed.
Black body bags are far better than white ones for fire victims. There is simply too great a brightness range, between white plastic and black charred subjects, for the average film or camera to encompass. If you increase the exposure for two black or dark objects, neither will be excessively overexposed, whereas a white object in the same field would probably "burn out" (become seriously overexposed).
When making videos, follow the basic rules of motion picture photography:
It's hard to do your own photography and keep your hands and equipment clean when working in the sooty mess that follows a fire. It helps to have an assistant, and it makes the investigation more efficient.
Don't let anyone try to qualify you as an expert in photography, unless you really are. It's usually better to qualify as a regular user and practitioner. Know what equipment and film or digital camera you used, plus how you set it, and simply stick with and attest to the fairness and accuracy of the photographs you took, or saw being taken.
Have you considered a question about chain of custody of your photographs during processing? Do you know which lab processes your photographs, or who does the work?
With digital photography, have you instituted a policy of burning your images to a CD-ROM as quickly as possible, then making all subsequent images by duplicating the original which remains completely unaltered? This can eliminate many criticisms and possible allegations. For instance, if you have one of the portable $200 devices that takes images from a solid-state card and burns them onto CD-ROMs at the scene, when you don't have computer, it's hard to allege that you altered or did something to the images. Make two CDs, so that one becomes part of the permanent record, and the other becomes the working copy for making prints. Be sure to mark your CDs with a solvent-free (CD-safe) pen, because some "write on anything" marking pens contain solvents that can damage CDs.
Curling's ulcers, involving the stomach and duodenum, are a form of bodily over-reaction to the insult of severe burns. Medical science is better at preventing these ulcerations than it was years ago, but it is not long (perhaps 15 years) since significant perforation or bleeding would occur from the stomach and/or duodenum in about 10% of burn cases (1/2 stomach, 1/3 duodenum, 1/6 from stomach and duodenum combined).
In practical terms this means that a person may be severely burned, survive for while and then develop significant bleeding from the intestinal tract, or even perforate an ulcer of the upper tract into the abdominal cavity. Severe blood loss or serious infection of the abdominal cavity (peritonitis) may follow, and lead on to death.
Such events may perplex law enforcement officers and the District Attorney, because the doctors at the hospital may be talking about ulcers and infections when everyone else is ready to charge someone with throwing gasoline. The problem is that the medical staff failed to trace the unbroken downhill sequence back to the initiating event, which was the thermal burns that gave rise to the ulcers.
Severity of a burn is a product of time, temperature, and cause, all combined. So, how do physicians grade or report the severity of a burn? Without going into needless details, you are likely to encounter the following methods:
a) By depth.
Roughly:1st degree (superficial partial thickness), involves epidermis
b) By the proportion, percentage, of the total body surface, which is involved.
Confusion can result from use of the term degree when it indicates the approximate extent of burning, in terms of the total body surface area (TBSA) or body surface area (BSA) that is involved:
Years ago very large burns were regarded as inevitably fatal, and very little could be done apart from making the patient/victim comfortable. Today, all burns are treated, and an amazing number that were inevitably fatal not many years ago are now survivable. Note however that inhalation (airway and lung) injury doubles the risk of death in burn cases, because of pneumonia and organ failure complications.
Note that large burns, involving 60% of the total body surface area are declining in number, also that small burns involving 10% or less of the body surface area are increasing.
So how does one estimate the percentage of the body surface area which is involved? There are several guides:
The "rule of nines", which applies only to normal adults:
Different figures must be used below the age of 15, because of different body proportions. Lund and Browder charts take into account the change in relative size of the various body parts as a child develops.
The "rule of palms".
The palm of a person's hand is roughly 1 % of the total body surface area. This is convenient for estimating the extent of small burned areas. It is not accurate for estimating large areas. Also, it does not seem to apply equally to all racial groups and may lead to over-estimation of burn area. It's a useful guide in the right circumstances.
c) The percentage of full or partial thickness of burn, is used by surgeons for purely practical reasons:
d) Burn index.
Burn index was devised at the Brook Army Medical Center burn unit. The index combines depth and area to better indicate severity, and the statistical outlook for injured patients.
[About 15-20 years ago 45 points meant a 50% probability of death in young adults, but this may no longer be true because treatment has improved so much in the last decade or two.]
Note: That the odds of survival vary considerably with age as well as in proportion to the amount of the body surface involved. Young adults, age 20-25, are the most likely to survive burns. Chances are worse for the very young and for the very old because of their lesser ability to tolerate injury.
e) Computer-based scanning techniques are relatively recent, and seem to be the most accurate.
Death from fire and burns need not be immediate, and is often delayed. If and when it's delayed, we will encounter the old problem of people losing sight of the initiating cause. Generally the process breaks down into three categories:
|Rapidity of death||Immediate causes|
|Rapid||Heat, hypoxia, CO, toxic products of fire in general, free radicals|
|First day||Fluid and electrolyte problems|
|Delayed||Infections and organ failures/shutdowns|
Probably, if the death was rapid and if the body will be refrigerated. More history will be valuable and this should help guide the autopsy. The body was probably in reasonably good shape prior to the fire, then the surface parts were heat sterilized and partially cooked.
Probably not, if death was delayed and the problems are mainly medical and infectious. The body is likely to deteriorate fairly rapidly because of bacterial infection, so within reason, the sooner you look at the body the better, before things change. If possible, try not to delay more than several hours.
Remnants of clothing, even if most of the clothing has been burned away, can be helpful in establishing identity. For instance the material from the tail of a shirt may be recognized by family members, as being similar to the known clothing of the deceased. Look for remains of clothing between the body and whatever it was lying upon or against.
Burn patterns are generally in accordance with the nature and distribution of clothing over the body surface, for instance less burning under a thick belt and waistband, but there are occasional exceptions with unusual fuels and whenever thinner clothing acts like a wick.
Clothing also helps with the preliminary sorting of bodies, for instance by gender and age.
Analysis of clothing remnants occasionally reveals traces of accelerants. If accelerants are suspected, put the article(s) of clothing in a new clean metal paint can to prevent evaporation. This is the main exception to the general rule that clothing should be dried before it's packed for storage. Packing damp or wet (non-burned) clothing in plastic bags, will cause it to mildew and/or rot. Items, other than those put into a can for accelerant analysis, should be air dried, and then packed in paper bags.
If in doubt, make a point of looking through the ash, or so-called "muck and ash" that is relatively close to the body. It may well contain keys, billfolds, purses, pocket knives, jewelry and all sorts of helpful things. Experienced fire investigators often sort through everything within 4-6 feet of a body.
If you find a lot of blood next to the body, be very suspicious. Its presence strongly suggests the presence of injuries prior to the fire. Bodies that are affected by heat tend to seal themselves off, just as a steak may be seared to retain natural juices.
I recall a case in which identification was considered hopeless, however I told the investigators to send all the charred fragments and clumps within a foot or two of the body. Within five minutes of starting the examination I found a melted vinyl purse, in which were the victim's check book, drivers license and other such items, most of which were quite well preserved and easy to read.
Handgun and rifle cartridges can "cook off' when exposed to heat both inside a weapon, or prior to loading. Bullets coming from cartridges lying around in a box, or loose, develop very low velocities. Even a military rifle cartridge supported at one end is unlikely to give a bullet more than about 150 - 200 fUsec. Cartridge cases and primers may fly around, but pose little hazard unless you happen to get one in the eye. If you suspect that a bullet may not have come from a gun, but simply cooked off in the heat, check for the absence of land and groove impressions on the sides of the bullet, and the absence of firing pin impressions on the cartridge cases. Only a bullet that came down a barrel will have land and groove impressions.
The exact temperature at which the various components will cook off is not entirely clear. A recent study indicated that common .22 rim fire cartridges will go off at about 330-403°F (151-192°C). To date I haven't found many credible references to the ignition temperature of ammunition, figures for which must vary somewhat according to how and where the heat was applied.
Various figures are quoted for ignition of cartridge components, e.g.
The very similarity of these figures suggests they may have been mixed up, or that primers and powder were tested together, in primed cartridge cases.
More recently, I came across the following figures on the Internet. I can't vouch for their accuracy, but they "feel" about right:
|Black powder||Gunpowder (double base)||Nitroglycerine|
necessary to ignite
at a constant volume
|Approximate burning rate,
at 1 atmosphere
|1/14 inch per sec
1.8 mm per sec
|1/360 inch per sec
0.07 mm per sec
|1/170 inch per sec
0.15 mm per sec
For the techies, the melting point of ingot iron and carbon steels is in the range of about 2,600- 2,800°F (1,430-1 ,540°C) so you will see why there's heat erosion (also called throat erosion) due to the heat and pressure that occurs in the first part of some rifle barrels.
I don't have any better figures than these at the moment. The point is Simply that ignition temperatures are relatively low, say very roughly 1 1/2 to 3 times that of boiling water. This fits well with the tendency, in years past, of overheated machine guns to keep firing in battle after the trigger was released.
Great advances in understanding have been made in recent years because of high-tech sampling and analysis, combined with computer simulations. Interest grew, and research really got going, after the air crashes in Denver in 1961 and Salt Lake City in 1965.
It's not just a matter of heat and carbon monoxide.
There is considerable correlation between the conditions of the fire and what is produced because the physical conditions determine to a large extent how the chemical substances break down and recombine. For instance it requires 1, 128°F (609°C) to convert carbon monoxide to carbon dioxide. Many such details are now known to those who study the chemistry and dynamics of fire. That's not my field, but it's interesting, and I'd like to know more.
There are all manner of nasty substances, including free radicals, running around in the fire atmosphere. If the post-fire atmosphere makes your eyes water, you don't need to breath it into your lungs, so keep your respirator or breathing apparatus on and continue breathing clean air for a while longer after most of the fire is put out. Some of these highly reactive chemicals may be related to the increased incidence of heart attacks in firemen, and some may even cause cancer. If you look at some of the studies, there is a higher incidence of bladder cancer, which suggests that cancer causing chemicals are getting into the body, and being excreted in the urine. We don't have all the necessary information as yet, so err on the safe side and when in doubt breath clean air, even if it does feel hot and confining.
For instance it takes hot steam to get heat far down into the airways. The circumstances and conditions of a fire can tell you a lot about the likely mechanisms of injury, and what to expect at an autopsy.
a) Cremation is the process of reducing human remains to bone and tooth fragments by the use of heat and evaporation. In the United States, using a gas-fired furnace, the process of cremation usually takes about 2 - 3 hours at a temperature of 1,500 - 1 ,900°F (815 - 1,040°C), including cool down time, or alternatively, more than 1 hour at 2,600°F (1 ,425°C). After this, the cremains (cremated remains), consisting of ash and bone fragments, usually weigh about 4-8 lb, according to the size of the adult body.
In short, it takes a great deal of external heat to reduce a human adult to a few pounds of ash. For a while I couldn't find any reliable figures, but in recent months I've had better luck, largely because of the Internet. My latest, and seemingly most credible, figures are the energy equivalent of:
If these figures are anywhere close to correct, and making allowance for heat loss outdoors, we can think in roughly equivalent (enclosed furnace/container) terms of:
I'm still looking for figures, but it stands to reason that bodies cannot burn completely away unless they're exposed to things like the prolonged and intense heat of chemical, industrial, and refinery fires.
If this isn't convincing, there is a move to reduce the amount of energy devoted to, and the pollution derived from, the present cremation process. It has been proposed that bodies be treated sequentially with liquid nitrogen and then steam, culminating in an hygienic powder, amounting to about a quarter of the live body weight, which would break down rapidly, and could therefore be buried quite superficially.
(b) Ordinary house fires seldom result in complete destruction of adult bodies, or even most children. They are not hot enough, or sufficiently prolonged.
(c) Small children and small animals can, and occasionally seem to completely consumed, but not often. It is possible, and more likely that they wi" not be found following a house fire if they were young and/or small, and the search was not thorough enough. What and how much people find is roughly proportional to the amount of time and effort they devoted to sorting through debris and sifting the ashes. It's often hands and knees work, followed by a lot of sieving/screening and sorting. Only that kind of effort will reveal remnants of teeth.
(d) Large chemical fires can burn intensely for far longer periods than house fires, and may be far hotter, so they may eventually destroy large adult bodies. Bodies will burn up any time there's enough heat and oxygen for a sufficient period of time.
These vary widely and can mean a lot to fire experts, so remember to ask, and if you are there at the time of the fire, take good photographs. (See the section on photography).
Note that some chemical foams and extinguishing agents may interfere with certain chemical tests. If in doubt check with a forensic toxicologist.
From an investigative perspective, it makes little sense to displace all the evidence with a jet or intense stream of water, throw it out of the building, and then wonder why one's having difficulty working out what happened, and/or what caused the fire. It's yet another way to destroy evidence. It's usually the result of shortage of time and personnel.
Toxicology forms an integral part of the fire investigation. In fact it's more important than in many other types of cases, because of carbon monoxide and the other by-products of fire.
The fire environment contains many different chemicals that are formed by the action of heat on materials (pyrolysis). Some are relatively easy to detect while others are not. They include free radicals which are parts of molecules, looking for something to attach to, which are particularly irritant and damaging to the lungs. A large proportion of persons dying in house fires, die from smoke inhalation and carbon monoxide polsoninq, and are heated or burned later, as the fire progresses.
Just because a body looks bad on the outside doesn't mean that you should alter your routine of testing for carbon monoxide, alcohol, and drugs (both abusive and medicinal).
We can't measure the carbon dioxide (dioxide, not monoxide) in a body in a meaningful way after death, but this gas is clearly a factor in some fire cases.
You should request carbon monoxide saturation, and blood alcohol concentration tests as an absolute minimum, and add routine drug screening in the case of anyone who might be an abuser, or who may have been taking drugs for medical reasons.
Carbon monoxide will be reviewed separately because it's so important in fire-related cases.
Draw blood, urine, vitreous, and bile if possible, so you'll be able to compare the alcohol concentration in three or four separate specimens. The idea is to use the various specimens to cross-check and verify each other.
Importance of correct sampling techniques.
(e.g. A car crashes and burns. The body of the sole occupant/driver is severely damaged by the subsequent fire. One of the locals sticks a needle through the chest wall, and wonders why the blood contains 2% of alcohol (not 0.2%) when the result comes back two weeks later! Question - where was the tip of the needle when the so-called blood was drawn? Perhaps the stomach that contained recently ingested beer ruptured into the left chest at the time of the impact? Such an approach to the procurement of important specimens is idiotic. They should have been drawn from a major blood vessel instead, or failing this through a small incision).
Remember the basic principles of forensic toxicology, especially the importance of sending sufficient material to the laboratory to allow proper testing.
As a guide send not less than the following minimum amounts of fluids and tissue:
Having obtained the materials from the body, send the following information to the laboratory with the specimens, even if the lab personnel don't ask for it, or show any interest in receiving it.
With a suitable form, all this information can be conveyed with a few words, circles and check marks.
It's also important to know a little about the test methods used within the laboratory itself. If you're dealing with a first class forensic laboratory, that's fine, but in rural areas, the Coroner may use the lab in a local hospital. The problem is that hospitals often test for alcohol by a method, called alcohol dehydrogenase, which only detects the kind of alcohol you and I would consume (grain alcohol, ethyl alcohol, ethanol).
However, serious/dedicated/dyed-in-the-wool/career alcoholics may drink:
So, you could have a case in which a hospital lab, that doesn't use a method capable of detecting all the common alcohols, report the result of the blood alcohol as negative, yet the victim may have been intoxicated with, say, rubbing alcohol. The method they employ simply doesn't detect it.
So, it's highly desirable to use a lab that has a gas chromatograph to pick up all the common alcohols, plus acetone (from starvation, diabetic acidosis or from metabolizing rubbing alcohol), and even a few of the common volatiles, (from glue, paint thinner, and solvent sniffing).
Another limitation of hospital laboratories is that they are seldom set-up to analyze clotted blood. Blood from living patients is usually fluid so they haven't set up the methods and procedures applicable to clotted blood. Any lab that is doing work for a major trauma center, or occasional Coroner's work, should be prepared to look for alcohols and carbon monoxide in clotted blood.
So, if you have regular contact with a particular hospital lab, take the time to find out what their methods are, and what, in fact, they are capable of detecting.
It pays to examine the bodies of any animals which are found dead at the scene of a suspected carbon monoxide or fire death. Most elected officials:
I mention this particularly with respect to carbon monoxide, but if a person is dead of smoke inhalation, an animal exposed to the same atmosphere should be dead also. In years past, well before the days of gas detectors, miners used to take caged birds (canaries) down the mines with them for safety. If the birds collapsed it was time for the humans to leave. If a human is found in a fire and foul play is suspected, be sure to examine the dead animals too.
In reality it is quite common to autopsy animals found dead with humans. You can run carbon monoxide tests just as easily on the blood of dogs, cats and most other pet animals and birds, as you can in humans.
In a few places you could run into a situation where it is the responsibility of animal control to deal with and dispose of dead animals. In such cases they may not be aware of the evidence that may be lost by failing to examine them. You may even have to seek an injunction through the district attorney.
No review of this kind would be complete without mention of child abuse and burned children. Not only is child abuse a thing of concern, but many abusive injuries take the form of thermal burns (usually with a hot fluid, or sometimes a hot object, as opposed to flame burns), so they must be included in a review such as this.
There are also many accidental injuries. Each year about 35,000 - 40,000 children are treated for hot water burns. It is said that about 70% of such accidental burns result from scalding with hot fluids, as when a child is in the bath, or pulls on a saucepan handle. One Shriners Burns Institute study showed that about 85% were less than 3 years of age, and the other 15% aged 4-15 years.
The following brief notes should further understanding:
a) About 10% of child abuse is perpetrated by burning.
b) About 10% of children admitted to bum units have injuries that are not accidental.
c) Many people don't know how to distinguish a scald from a flame burn, or even that it is possible.
d) If you study burns in children under the age of 10 years, you are likely find numbers that are similar to:
Note that burn area is not very different in the two groups but that the age is distinct. Eventually you will come to realize that a child under the age of 1 year is unlikely to be burned accidentally, unless it is involved in a house fire or something. But the same age of child, causing aggravation by screaming and/or giving problems with diapers, is quite likely to be abused. In effect, a very young child isn't yet smart enough to keep itself out of trouble with angry, short tempered or intoxicated adults.
e) Analysis of the mechanism of injury reveals figures like:
Normally, above the age of 4, there is little or no thermal abuse, because by then, children have wised up, take care not to offend, and stay well clear way of adults who might harm them. However there is are exceptions with special groups, such as the mentally retarded.
The accidentally injured child is at greatest risk just after becoming relatively mobile and getting into things before learning, often the hard way, how to stay out of harm's way.
Abuse is more likely to arise from tap water, whereas accidental injury comes from other hot liquids, such as grease, coffee, tea or soup, and from pans on a stove - much as one would anticipate. To over-simplify, the average abusive adult doesn't usually make coffee to pour on a child. Tale a good look at the overall picture and things may stand out.
f) The distribution of burns is important, particularly the depth and severity within an individual burn.
Think of it this way, (and let's suppose you are evaluating a burn involving the hand and lower half of the forearm of a child of an age such that it might have been abuse, or accidental) and that you are trying to decide which it probably was.
If the child approached a pail of hot water standing on the floor, and immersed his hand, about the time the hot liquid hit the lower forearm the child would already have "decided" that the water was far too hot and that the hand had to come out. So the fingers would go in first and then the water level would move up the fingers, across the palm, over the wrist and then up to the mid forearm. At this moment the motion reversed and the water level went back down towards the fingers. This means that the fingers were immersed for a significantly longer period than the wrist, and the skin near the uppermost part of the forearm for the shortest time. Thus if the child did the moving, the burn should be deeper and more severe, at the fingers and far more superficial, less severe, at the mid forearm.
If however it was a case of abuse, the child might have been grabbed by the left upper arm and the upper right forearm. The perpetrator then forced the right hand and lower forearm into the water and held it there with the child thrashing and screaming but unable to withdraw. The extremity might have been immersed for as much as 10 seconds. There will be little difference in the depth and severity of the burn throughout its length because the fingers were immersed for 10 seconds and the lower forearm for over 9 seconds, which isn't much difference. Thus, there isn't the progressive change, or gradation of depth, seen in the rapid in-and-out situation.
Of course there are exceptions, such as when hot viscous liquids do not drain off immediately (oil or napalm) or if the accident victim cannot get out of hot fluid fast enough for some other reason, such as lack of a handhold. The circumstances, as revealed by the investigation, wi" be the key most of the time.
Note that if a child really did appear to sustain an accidental burn in a bath tub, it may be a good idea to measure the slope or inclination of the bottom of the tub. This helps with body positioning and subsequent scene reconstruction. Also note how much turning force is required to turn the taps or push the levers. A child can't turn a tap that an adult finds hard to move. If a faucet is loose and/or worn, it's very different. Lever style handles are different again.
You must use common sense. Unless there was great difference in depth or severity, you would find it hard to distinguish between the burns on the palmar surface of the hand and fingers of a child who:
So it's very important to ask the treating physician for detailed information concerning, the distribution and depth of the burns, and to chart the distribution and depth very carefully. That rings us back to photography and drawing the injuries on outline diagrams of the body.
g) Who causes thermal abuse?
h) Flame type burns may be harder to evaluate than hot liquids because of their lesser size. For instance was it a hot piece of metal, or a hot utensil?
i) X-rays are important in cases of suspected child abuse. It's not quite the same as in adults but it is equally helpful. Just as it is desirable to find an unexpected bullet in a badly burned adult found dead in house fire, so it's helpful to find a variety of unsuspected healing fractures in the skeleton of an abused, and subsequently burned, child.
j) Common sense safety measures include: not leaving a child alone in the bath, testing the water properly before putting a child in, facing the child away from the taps and fixtures, thinking about installing anti-scald devices, making sure the water heater isn't set excessively hot, not establishing the kitchen as a recreational area, and keeping hot things out of reach.
Don't proclaim child abuse too soon. Unfortunately people tend to over react and over diagnose abuse; and to make matters worse, some of the child welfare agencies are inadequately regulated. Much injustice is done. Strange things can and do happen, but histories are often overtly absurd! (Three month old babies, who are barely mobile, seldom conveniently and suddenly fallinto buckets of hot water that just happen to be standing by their bedsides!)
Don't say too much, too soon, to the wrong persons. Be suspicious by all means, but keep an open mind. Observe everything, and document carefully and thoroughly, particularly the distribution of burns in the body position alleged at the time of injury.
Be on a constant look out for one or more of the following warning signs of abuse:
Before moving on, it is appropriate to mention some practical safety measures to help prevent accidental scalds in children:
For detailed information on maintenance and repair of water heaters, see "The Water Heater Workbook", by Larry and Suzanne Weingarten, 1992. Elemental Enterprises, P. O. Box 928, Monterey, CA 93942. (408) 394-7077.154 pages, soft cover @ $20.
In the middle of a star at many millions of degrees, a body would turn to ash and vapor in some minute part of a second. On the other hand we could, in theory, remain in water at our normal skin temperature until we became waterlogged, but we'd never, ever, burn. Between these two hypothetical extremes, damage occurs more rapidly as temperatures increase. Heat transfer is generally in proportion to temperature difference.
High quality books describing the treatment for burns, often quite figures such as:
Burning occurs more rapidly than many believe to be possible, especially at higher temperatures. A few studies have been done, but research is obviously limited by the lack of enthusiastic volunteers! Nevertheless, the studies that have been done, give us a pretty good idea of the speed at which burning occurs from hot metal or water.
I am unable to verify the following figures from personal experience, but I have every reason to believe they constitute a reasonable guide for use in our work. However I deliberately used the word guide, because I have never seen a logical discussion of factors such as skin thickness, part of the body, racial ancestry, skin pigmentation, vascularity, arterial and venous flow rates, age, and physics of heat transfer together. (It's much like the studies of bullet velocity necessary to penetrate human skin that don't mention the shape, size or weight of the bullets, not the age, gender and parts of the skin that was tested.)
If you wish to go into detail, note that the older articles may use slightly different terminology especially when it comes to the depth of a burn. Therefore studies separated by a period of years may not be exactly comparable, and it's particularly likely that studies done by pathologists may not employ the same definitions of the depth/extent of burns as those used by surgeons.
As an approximate guide, the time needed for a deep burn, in an adult is:
Children burn more rapidly, so the approximate time needed for a child to get a full thickness burn from hot water is:
At the bottom of page 98 of the January 1998 issue of Popular Mechanics magazine I found a chart of times that was said to be used by the US Consumer Product Safety Commission:
|1st degree burn||2nd or 3rd degree burn||Water temperature|
|35 min||45 min||116°F|
|1 min||5 min||122°F|
|5 sec||25 sec||131°F|
|2 sec||5 sec||140°F|
|1 sec||2 sec||149°F|
This table doesn't indicate if it is applicable to children or adults, and "instantaneous" is not scientific, but it's worthy of inclusion because (a) the figures are similar to the others, and also because (b) people often regard such government-sponsored tables as totally credible, and may refer to them blindly, without any thought.
A brochure printed by the Chicago Faucet Company in 1995, included the words, "As water temperature decreases, so does the chance of a third degree burn. Then followed a bar graph, the basis and origin of which was not specified:
Regardless of the exact numbers, or the methods by which they were obtained (hot solid objects vs. hot water), if bath water reaches about 140-150oF, a person cannot pull a child out fast enough to prevent a burn, even if they immediately become aware that the water's too hot.
Conversely if the water temperature is kept below 120°F (49°C) a child is fairly safe. If people live in an apartment, and cannot install a modern tub/shower valve, there are alternatives, such as:
So prevention sounds easy, but as with most things water temperature is a compromise. If the temperature is too low there may be bacterial contamination, and/or the water may not be hot enough (130°F) to deal with dust mites in bedding, kill off bacteria in towels and clothing, or allow adequate cleansing of dishes (135-140°F) by dishwashers that don't have booster heaters to get the water to about 180°F to sterilize them.
A question you may, sooner or later, be asked is "what is a comfortable shower temperature"? I suggest you borrow an accurate thermometer (e.g. one from a laboratory), take a shower and set the water temperature so that it feels just right. Then measure the temperature immediately after the water leaves the shower head, and then a little lower down where the water hits your body. There will be a slight difference. Then, to "ice the cake", reduce the temperature slightly to a point at which you'd prefer it a shade warmer, andthen increase it to a point at which you'd prefer it a shade cooler. That will give you three reliable figures that suit you individually, and will help you to answer the question, assuming of course that you're not a devotee of exceptionally cold or hot showers.
Personally, I find that water for a comfortable shower leaves the head at about 104°F (40°C) and hits me when it's about 1°F cooler.
I strongly advocate shower controls that:
There are several good ones, by major manufacturers. I bought one in August 2002 for only $121.23 including sales tax. They effectively eliminate scalding, and hold temperature so well that they're a pleasure to use. Since the flow can be adjusted without changing the temperature they also save water, if only because you can vary the flow for various tasks such as showering and rinsing your hair. Personally I like to run a shower at about 1-1% US gallons per minute, not like a fire hose, as some seem to do.
The key point is that the relationship between water temperature and the time taken to burn is non-linear, and as temperatures rise, the time required to produce a burn shortens dramatically, in a way that many, perhaps the majority, do not understand.
Thus, there are variations on the theme of time, including:
At the time the water temperature is being measured it is sound practice to measure the maximum flow rate of hot water, to see if a tub could really have filled as fast described if the phone rang, or a child really could or did turn the hot water "full-on" accidentally.
So here's a short check list for "child in hot water" problems, not in order of importance:
From this, in an immersion burn case, it's obvious that it would be a good idea to estimate the level of the high water mark at the time of an autopsy. If the burn is roughly 12 inches "deep" and the sink is only 7 inches deep then the burn probably didn't occur in the sink, as might be claimed.
Consider videotaping any such investigations, or take a full set of photographs as you proceed.
Documentation of shower temperature and flow rates is much the same. There's a lot of stupidity in the literature about being scalded by shower water. There is some sense to it of course, but so much of it is overdone. We all know that some people like cold showers, and some like them hot. One manufacturer's catalog states that the comfort range is between 90°F and 100°F, which raises the question of what is the normal temperature for a shower? If you investigate hot water problems you should know what's right for you. Hence my previous comments.
In short, the only fixtures that make sense to me are the modern pressure-balanced valves that have separate dials for flow and temperature, or second best, entirely separate hot and cold controls that can be adjusted long before wetting the skin.
Some would say that single control valves are acceptably safe, by in my experience this is not so. This is because some of the older ones were designed to supply water to unrestricted heads. However, if one of the flow-limiting heads is substituted to save water, the valves are exposed to a back pressure for which there were never designed. After years of experience in hundreds of hotels I found that many of the combined "joystick" (flow and temperature combined) regulators are unpredictable, and take a lot of getting used to. I've had a number of unpleasant experiences with them in (quite good) hotels.
One way it can happen is this. You step into a tub, and see an older valve with a single control, which may be a bit loose. You turn the water on, but let it run into the tub until the temperature is nearly right, then pull up or down on the diverter. A blast of far hotter water comes out of the shower head, because the valve is suddenly exposed to back pressure from the flow restricted head instead of a free flowing spout.
So much for fluids. Now let's think about solid surfaces.
You may wonder why even more figures are potentially useful, so I'll outline an example. In November 2003, a friend contacted me about a case involving a young adult male who had committed suicide by hanging after being arrested and put in a cell. The circumstances leading up to the arrest don't matter much in an educational context, but it was soon claimed that he was not observed with sufficient frequency to prevent his self-induced death. At autopsy some burns were poorly described, and no photos were taken, but he hanged himself in such a way that his body came to rest against a metal radiator. He was seen alive at one time, then found hanging about 25-30 minutes later. Therefore, people wanted to know if he hanged himself just after the time when was last seen alive or not long before he was found hanging. It was claimed that the temperature of the jail radiators had been limited to 115°F, to prevent the prisoners from burning themselves and each other, but roughly two years had elapsed since the death, so taking temperature measurements at such a late date didn't seem worth the effort. If they were hot people would claim they had changed, and if they were too cool to cause such burns it wouldn't have helped. The question then became what sorts of surface finishes and temperatures would have been "safe" for the skin. This led to the thought of safety standards for domestic appliances, and in due course I found some figures on the Web site of the Royal Society from Prevention of Accidents in the UK. Here are some excerpts from an 8-page article.
EN 563: 1994 Safety of machinery - Temperature of touchable surfaces - Ergonomics data to establish temperature limit values for hot surfaces.
|Uncoated metal||65°C — 149.0°F||58°C — 136.4°F||55°C — 131.0°F||48°C — 118.4°F||43°C — 109.4°F|
|Painted metal||83°C — 181.4°F||64°C — 147.2°F||55°C — 131.0°F||48°C — 118.4°F||43°C — 109.4°F|
|Enameled metals||74°C — 162.5°F||60°C — 140.0°F||56°C — 132.8°F||48°C — 118.4°F||43°C — 109.4°F|
|Ceramics, glass, stone||80°C — 176.0°F||70°C — 158.0°F||66°C — 150.8°F||48°C — 118.4°F||43°C — 109.4°F|
|Plastics||85°C — 185.0°F||74°C — 165.2°F||70°C — 158.0°F||48°C — 118.4°F||43°C — 109.4°F|
|Wood||110°C — 230.0°F||93°C — 199.4°F||89°C — 192.2°F||48°C — 118.4°F||43°C — 109.4°F|
The likely contact times were seemingly chosen as being representative of daily activities:
|1 sec||Accidental contact with oven doors and the sides of toasters|
|4 sec||Parts held for short periods, such as knobs and switches|
|10 sec||Parts continuously held in normal use, such as handles|
|10 mins||Prolonged use, such as handles|
|8 hours||Continuous use, such as handles|
The next table indicates upper burn threshold limit values for various surfaces for an unintentional contact period of 1 second.
|Uncoated metal||70°C — 158.0°F|
|Heavily coated metal||95°C — 203.0°F|
|Ceramics, qlass, stone||86°C — 186.8°F|
|Plastics||94°C — 201.2°F|
|Wood||140°C — 284.0°F|
So, as you will see, assuming that the radiator in question was metal and painted, these values served as a guide to the combination of time and temperature it would have taken to burn the skin of a young adult person. If the radiator was indeed at 115°F (46.1°C) a burn would make sense if his skin was in contact with the radiator for more than 10 minutes (let's say closer to 15 minutes for our purposes here). This estimate would move the time at which he hung himself closer to the time when he was last seen alive.
You can find the whole article, and references to the safety standards, under the heading "Temperatures of touchable surfaces" at: www.rospa.com/CMS/index.asp
So, it's nice to have a collection of numbers to serve as a guide, when trying to reconstruct the circumstances surrounding a death or an injury. However they are only guides, and one must apply a liberal amount of common sense, because touching a hot toaster or a handle with the thicker skin of a manual worker's hands is not the same as the less keratinized skin of the trunk. Those who's hearts have partially or completely ceased to pump blood, do not have the normal circulation to carry heat away from the affected portions of skin, are likely to burn a bit faster that would someone with a good circulation. Children and the elderly burn sooner that young healthy adults, frequently male, on whom much of the research has been done. In short, we should expect variations from person to person, and situation to situation.
These are mentioned mainly for sake of completeness.
Remember also that there are burns due to exposure to nuclear explosions, and other caused by accidents involving radioactive materials. Neither of these are day-to-day problems, but the possibility should not be forgotten.
No discussion of fire-related deaths would be complete without brief mention of smoke detectors. Smoke detectors were first marketed in 1969. Today an estimated 93% of US homes are equipped with them, but many are not in proper working order because of failure to check and maintain them, and/or to replace their batteries.
Combined ionization and photoelectric:
Why do people still die when detectors are present? Too often because the detectors are inoperative, and all too often for some stupid reason such as dead batteries. For example, surveys have reported that smoke detector batteries are missing or dead in more than 90% of deaths due to fires in homes equipped with detectors. An estimated 23% of persons don't check their batteries often enough, and as many as 8% think they are dead, but do nothing about it. For this reason, many experts advise the use of mains (115v) powered detectors, or making detectors part of an alarm system which incorporates back-up power, or establishing a routine such as checking batteries when the clocks are moved back an hour in October. The thinking is that heating will be used more in winter than in summer.
Occasionally a human body is found burned in unusual circumstances. Usually the body is found indoors in a relatively small room or equally confined space. The trunk may be largely burned away while parts of the limbs and head remain intact. The upper part of the interior of the room is often coated with greasy residues and soot, plastic items such as televisions may have partly melted, and metal objects may be warm or even hot to the touch.
Until a better understanding of fire dynamics and combustion processes were developed, some people felt that the body had somehow caught fire spontaneously, and advanced a number of scientifically and technically unfounded theories to explain these peculiar observations. Even today outrageous theories are being advanced, and much is made of such cases, often for profit. There is no reason to believe that a body can self-ignite, because most body parts require more heat to burn them than they can generate by burning. If this were not so, bodies could be cremated by lighting them with an acetylene torch, and there would be no need for crematoria, funeral pyres, and the like. Furthermore, if bodies did burn fairly well, it would have been a public spectacle at some time in the past, much like public executions. Burning people at the stake in the middle ages required chains to keep them in place, also large piles of wood to kill them and partly destroy their bodies.
Investigation of "unusual" burned-body situations (spontaneous combustion) usually reveals that most of the following conditions are present:
Helpful figures include:
Thus, very occasionally a body is ignited by a nearby source of heat in a fashion such that a flame is started, fat melts, clothing, bedding, or something else such as carpet serves as a wick, and those parts of the body where there is ample fat slowly burn, much like a candle, sometimes but not necessarily in conditions of slightly reduced oxygen, slowly destroying the body, partly ashing the bones and eventually self-extinguishing when most of the fat has been consumed, leaving parts of one of more limbs and/or the head intact. Any alcohol the individual may have consumed has nothing to do with it, because the concentration <1/2% in water) is far too low to be relevant.
Hence the appearance of localized severe damage to a body, in largely undamaged, albeit greasy, moist and smoky surroundings. If a few cases remain unexplained it's probably because the source of ignition, such as a cigarette, was itself burned away.
In short, there may be human combustion, but it's not spontaneous!
The reality is that a surprising number of people don't understand fire, the fire environment, what fires can do to a body, nor the problems created by fire for those who have to examine one or more victims.
Bodily features, including apparent injuries, may even result from the processes of fire fighting and post-fire overhaul. Even some of the chemicals used in fighting fires can cause problems for the toxicologist if they contaminate the blood and body fluids.
Investigation of fire and bums is a team effort. A good pathologist needs information from the fire investigator, every bit as much as the investigator needs information from the pathologist. There should be a free exchange of information, but all too often this doesn't take place. We should do our utmost to see that the necessary information is made available. We may even need help from other experts, such as forensic dentists or forensic anthropologists.
When fires are investigated it is possible to determine the cause about 85% of the time, but this still leaves 10 - 15% with undetermined cause. This is because fire, by its very nature, destroys the clues and/or the causes, making them unavailable to the investigator.
Finally the interpretation of fire-related deaths. Make absolutely sure to distinguish between:
Above all, don't hesitate to say "I don't know". Many times, too often in fact, it's the right answer.
Patrick Besant-Matthews, M.D. is a highly acclaimed and popular consultant and lecturer in the area of forensic medicine and criminalistics. He is the former Deputy Chief Medical Examiner for Dallas County, and Chief Medical Examiner for Seattle/Kings County.
He has presented thousands of programs to nurses, physicians, law enforcement officials, and various scientific groups. He is also an experienced expert witness, and is highly skilled in the area of medical photography. Dr. Besant-Matthews was an integral contributor to the origination of the American Association of Forensic Nurses. His expertise in his field, his sense of humor, and his flair for drama combine to produce a highly enjoyable seminar.
Burns, Fire and Arson Deaths and Injuries Copyright: © 2004 by Patrick Besant-Matthews, M.D.. Copyright for this article is retained by the author, with publication rights granted to the Crime Scene Investigation Network. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License which permits unrestricted noncommercial use, distribution, and reproduction, provided the original work is properly cited and not changed in any way. Based on a work at http://www.crime-scene-investigator.net/burns-fire-and-arson-deaths-and-injuries.html.
Article submitted by the author. The Crime Scene Investigator Network gratefully acknowledges the author for allowing us to reproduce the article .
Article posted September 16, 2019