Algor Mortis

The term “algor mortis” means “cold death” in Latin, and it refers to the temperature shift that occurs after someone has died.

The cooling of the body temperature after death is known as Algor Mortis. Algor mortis can be used up to 24 hours after death. Our metabolism maintains our core body temperature at around 98.6°F (37.0°C) throughout our lives. Death and the absence of metabolism allow the body to ultimately adopt the temperature of its surroundings. The temperature of the cadaver progressively drops due to convection, radiation, conduction, and fluid evaporation until it reaches an equilibrium with the environment, which usually takes 18–20 hours. The cooling pace is determined by the temperature difference between the corpse and its surroundings; hence, a larger temperature difference between the surrounding environment and the body leads to faster cooling. Body temperature is usually kept constant for 30 minutes to an hour after death before starting to drop, however this might last up to 5 hours in severe situations.

If the temperature outside is 110°F (43.3°C), the body temperature will rise. In forensic pathology, it is generally recognised that between between 2 and 12 hours after death, the corpse cools at a rate of 1.5°F (0.94°C) each hour at the normal temperature of 70°F (21.1°C). After around 12 hours, the body temperature reaches normal temperature. In fact, predicting the pace of cooling is challenging since these ideal circumstances are not always available, as the ambient temperature or initial body temperature may be unknown. The core temperature can be measured either rectally or by inserting a probe-type thermometer into the liver. In the field, temperatures and humidity levels are rarely normal. The pace of cooling can be affected by factors like as ambient temperature, humidity, clothing, body mass, and premortem hyperthermia or hypothermia. The core temperature can rise if the surroundings is warmer than the premortem body temperature. Algor mortis statistics are frequently coupled with additional Rigor Mortis and Livor Mortis results, as well as other investigative evidence, to establish a time range for death. There is no test that can predict the precise moment of death.

References:
  1. Igari Y, Hosokai Y, Funayama M. Rectal temperature-based death time estimation in infants. Leg Med (Tokyo). 2016 Mar;19:35-42. 

2. Wardak KS, Cina SJ. Algor mortis: an erroneous measurement following postmortem refrigeration. J Forensic Sci. 2011 Sep;56(5):1219-21.

3. Cockle DL, Bell LS. Human decomposition and the reliability of a ‘Universal’ model for post mortem interval estimations. Forensic Sci Int. 2015 Aug;253:136.e1-9.

4. Maile AE, Inoue CG, Barksdale LE, Carter DO. Toward a universal equation to estimate postmortem interval. Forensic Sci Int. 2017 Mar;272:150-153.