How much more do we not even know about our own body, not to mention the world around us. There is such a phenomenon - posthumous overheating. Until now, it is a big mystery for science. After death, some bodies, instead of cooling down, suddenly heat up to very high temperatures. Pathologists around the world have tried to explain the unusual temperature changes.
Here's what is known at the moment …
One morning in a Czech hospital, a 69-year-old man died of heart disease. An hour later, as the nurses were preparing to move the body to the autopsy laboratory, they noticed that the skin of the corpse was unusually warm. Calling a doctor to confirm the fact of death (and the man was indeed dead), the sisters decided to measure the temperature. It turned out that 1.5 hours after death, his body temperature was 40oC, about five degrees higher than his death temperature, although it was much colder in the ward itself.
Fearing tissue degradation due to overheating, the doctor and nurses sought to cool the body with ice, so that over time it cooled to a completely "cadaveric" temperature. The study of this unusual case was published in the American Journal of Forensic Medicine and Pathology (the link may be temporarily unavailable due to preventive work on the journal's website), and has nothing to do with the phenomenon of spontaneous human combustion.
Where does the heat come from
In a living organism, heat is generated due to the fact that it breaks down food with the release of heat energy. After death, metabolic processes stop, so the body cools quickly. This temperature difference is even used by pathologists and forensic scientists to determine the exact time of death of a patient. Unfortunately, the relationship between body temperature and time of death is not always so straightforward. In 1839, physician John Davey recorded unusually high temperatures in the bodies of British soldiers killed in Malta. Some of the corpses were heated to 46oC, although Davey suggested that a warm climate might have played a role. However, post-mortem overheating has been documented by many other doctors and forensic scientists.
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Peter Noble, a microbiologist at the University of Alabama who studies microbiome and gene expression changes after death, believes that research on post-mortem heat has not been thorough enough. Most of the research was not carried out by experts, and therefore a lot of data remains simply not documented, and it is impossible to build scientific hypotheses based on such conclusions. Many factors affect body temperature, including the amount of clothing and body fat thickness, ambient temperature and humidity. Physicians use a number of comparative characteristics to determine the time of death, including muscle stiffness, discoloration of the body, the degree of decay, and the population of the corpse with insects.
So what is the reason for the posthumous heating of corpses?
Be that as it may, today posthumous overheating of the body remains a mystery, and its causes, frequency of manifestation and the very fact of existence are still vague and inaccurate. Thoroughly studying the phenomenon is not possible, if only because it occurs spontaneously and not always in specialized hospitals. The factors that make the body more susceptible after death - cancer, intoxication, brain injury, asphyxia, heart attacks, etc. - also do not make the task easier. As for the heating itself, most experts just talk about "metabolic processes", without any specifics. The new study, for example, cites "prolonged tissue and bacterial metabolism and insufficient heat loss" as the cause.
Noble believes that a situation where heated blood (for example, as a result of strong physical exertion) stops abruptly due to sudden death, then the heat will indeed persist long enough, causing the body to heat up. An important role is played by drugs that manipulate blood flow. But rotting bacteria, according to the pathologist, cannot have a significant effect - the immune system is partially active for another 24 hours after death and autopsy, so bacterial growth is usually suppressed during these hours. Symbolic bacteria (such as intestinal bacteria) can still continue to decompose food, causing some heat. The cells of the body also do not die at the same time, and for some time they live on internal resources even after cardiac arrest and brain activity. CO2 that accumulates in the process and, finding no way out,begins to destroy the cells themselves, causes autolysis, or self-digestion. And this process can generate a certain amount of heat.
Summing up
Posthumous overheating is a mysterious and little-studied phenomenon, although well-documented. Many factors, if they happen to coincide in time and place of action, can cause partial heating of the body after death, but modern science cannot give an exact explanation. Perhaps, if someday doctors manage to simulate a similar situation and cause it artificially, in laboratory conditions, they will be able to give a clear conclusion. Until then, we can only build hypotheses.
One of the hypotheses was suggested by American pathologists who explained the phenomenon of postmortem hyperthermia, which is often observed in the first hour and a half after cardiac arrest.
Dr. Victor Weed emphasizes that posthumous hyperthermia has nothing to do with spontaneous combustion. Pathologists claim that the temperature of 60% of bodies can rise to 40 degrees in the first hour after death. In general, scientists consider this phenomenon to be poorly studied, but they already have a scientific hypothesis about the cause and course of the phenomenal process. Every medical student knows that the human body generates heat through the breakdown of food consumed. At the time of death, the physiological functions cease and the body loses temperature. In forensics, the body's cooling rate helps determine when death occurs. However, this indicator in 60% of cases cannot be taken into account. Microbiologist Peter Noble listed more than a dozen factors that affect the rate of rigor mortis. Scientists have foundthat intestinal bacteria continue to process food after the death of a person, which causes the production of a significant amount of heat. Often, it is gastric, intestinal bacteria and the presence of food in the digestive tract that cause the temperature of the dead body to rise to 40 degrees.