Early changes in the corpse are reliable signs of death. Forensic knowledge of the laws governing the development of changes in a corpse allows solving a number of expert tasks: the limitation of the onset of death, the initial and altered position of the corpse. Sometimes features of the fatal changes have diagnostic value, for example, in some types of poisoning, in exsanguination of the body, etc. The development and manifestation of early changes in a corpse depend on many external and internal factors. These changes that have expert value include: cooling, the formation of deformities and rigor muscle numbness and the initial period of dehydration, autolysis.
Cooling With the onset of biological death, metabolic processes cease and heat is generated by the body in the external environment, which leads to a gradual cooling of the corpse. A drop in temperature occurs until the temperature of the corpse is 0.5-1 ° C below the environment. The lower temperature of the corpse compared to the ambient temperature depends on evaporation from the surface of the skin of the corpse. At low temperatures (below 0 ° C) cooling of the body turns into a freezing corpse. The cooling rate is influenced by body weight and the severity of the subcutaneous fat layer. With exhaustion, cooling occurs faster, on the contrary, in obese people, this process proceeds more slowly. Equally important is the posture of the corpse and the nature of the clothes on it, the warmer it is, the slower the cooling develops. The corpses of newborns are cooled especially quickly, it depends on the greater surface of the skin in relation to body weight, and the very tender and thin epidermis of the newborn contributes to the intensive cooling of the corpse.Go
The rate of death of a corpse is also affected by the cause of death. So, if death occurred from tetanus during convulsions, from sepsis, typhus, mechanical asphyxiation and some poisonings, the temperature of the body after death for a short time may increase. According to some data, the body temperature over the next two hours after death can reach + 40 ° C and even higher.
Although many conditions affect the speed of a cadaver's temperature, however, at approximately normal room temperature (+ 16– + 18 ° C), the temperature drop of the body of the corpse has a certain regularity. Upon the onset of death, cooling is primarily noted on the open parts of the body: after 1 h, the coldness of the hands is noticeable, and after 2–3 hours - the skin of the face. Many researchers indicate that the temperature of a corpse falls by an average of 1 ° C per hour. According to other data, the fall in body temperature slows down after six hours: at 1 ° C it falls every 1.5-2 hours. For a more accurate determination regularities of the temperature of the corpse, which would take into account the ambient temperature, it is necessary to measure the temperature of the corpse after a certain time at the beginning and at the end of the inspection of the corpse at the site of detection, and then when the corpse enters the morgue while taking into account the surrounding temperature Reda. It is better to measure the temperature every 2 hours in order to establish benchmarks indicating the speed of its fall under given specific conditions. The temperature of the corpse, it is advisable to measure in the rectum. For a more accurate determination of the duration of death by the rate of temperature drop, a deep liver electrothermometry was proposed using an ETM-ZB electrothermometer.