Algor mortis (from
Latin algor 'coldness', and mortis 'of death'), the third
stage of death, is the change in
body temperature post mortem, until the ambient temperature is matched. This is generally a steady decline, although if the ambient temperature is above the body temperature (such as in a hot
desert), the change in temperature will be positive, as the (relatively) cooler body acclimates to the warmer environment. External factors can have a significant influence.
The term was first used by
Bennet Dowler in 1849.[1] The first published measurements of the intervals of temperature after death were done by
John Davy in 1839.[2][3]
Applicability
A measured rectal temperature can give some indication of the time of death. Although the
heat conduction which leads to body cooling follows an
exponential decay curve, it can be approximated as a linear process: 2 °C during the first hour and 1 °C per hour until the body nears ambient temperature.
Generally, temperature change is considered an inaccurate means of determining time of death, as the rate of change is affected by several key factors, including:[6]
Stability or fluctuation of the ambient temperature.
The thickness (i.e.
thermal insulation value) and body coverage of clothing or similar materials.