Cooling of the Body

Written by Dr. D. Rao

The cooling of the body Algor mortis; ‘chill death’] after death is a complex process, which does not occur at the same rate throughout the body. The body cools more rapidly on the surface and more slowly in the interior. For about half to one hour after death, the rectal temperature falls little or not at all. Then the cooling rate is relatively uniform in its slope. Then it gradually becomes slower as the temperature of the air is approached. The body heat is lost by conduction, convection and radiation. Only a small fraction of heat is lost by evaporation of fluid from the skin. In serious illness, circulation beings to fail before death, and hands and feet become cooler than the rest of the body; this coolness gradually extends towards the trunk.

Normal body temperature – rectal temperature


Rate of temperature fall per hour

It cannot be assumed that the body temperature is normal at death. in cases of fat or air embolism, certain infections, heatstroke and in pontine haemorrhage, drug reactions, etc. a sharp rise in temperature occurs. Exercise or struggle prior to death may raise the rectal temperature up to 1.5o to 2o C. Low temperature occurs in cases of collapse, congestive cardiac failure, etc. During sleep the rectal temperature is 0.5o to 1oC. lower.

Factors Affecting Rate of Cooling:
  1. The difference in temperature between the body and the medium.
  2. The build of the cadaver.
  3. The physique of the cadaver.
  4. The environment of the body.
  5. Covering on or around the body

Medico-legal Importance: It helps in the estimation of the time of death.

Postmortem caloricity: In this condition, the temperature of the body remains raised for the first two hours or so after death.

This occurs:

  1. when the regulation of heat production has been severely disturbed before death, as in sunstroke and in some nervous disorders,
  2. when there has been a great increase in heat production in the muscles due to convulsions, as in tetanus and strychnine poisoning, etc., and when there has been excessive bacterial activity, as in septicaemic condition cholera and other fevers.