# Algor mortis

Stages of death

Algor mortis (Latin: algor—coldness; mortis—of death) is the change in body temperature following death. This is generally a steady decline until matching ambient temperature, although external factors can have a significant influence. However, if the ambient temperature is above the body temperature (such as in a desert), the change in temperature will be positive as the (relatively) cooler body acclimates to the warmer environment.

## 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° Celsius during the first hour and 1° Celsius per hour until the body nears ambient temperature.

The Glaister equation[1][2] estimates the hours elapsed since death as a linear function of the rectal temperature:

$\frac{98.4\,^{\circ}{\rm F} - \text{rectal temperature in Fahrenheit}}{1.5}$

As decomposition occurs the internal body temperature tends to rise again.

## Variability

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:[3]

• Stability or fluctuation of the ambient temperature.
• The level and thickness of clothing or similar materials.
• The thermal conductivity of the surface on which a body lies.
• Diseases or drugs which increase body temperature raising the starting temperature of the corpse at the time of death
• The existence of a "temperature plateau",[4] a highly variable period of time in which the body does not cool.

## References

1. ^ http://www.fmap.archives.gla.ac.uk/DC403/DC403_page.htm
2. ^ Guharaj, P. V. (2003). "Cooling of the body (algor mortis)". Forensic Medicine (2nd ed.). Hyderabad: Longman Orient. pp. 61–62.
4. ^ Kaliszan, M. (20 May 2005). "Verification of the exponential model of body temperature decrease after death in pigs". Experimental Physiology 90 (5): 727–738. doi:10.1113/expphysiol.2005.030551.
• Saferstein, Richard (2004). Criminalistics An Introduction to Forensic Science (8th ed.). Pearson Prentice Hall. ISBN 0-13-113706-9.
• Karen T. Taylor, "Forensic art and illustration", CRC Press, 2000, ISBN 0-8493-8118-5, p. 308
• Robert G. Mayer, "Embalming: history, theory, and practice", McGraw-Hill Professional, 2005, ISBN 0-07-143950-1, p. 106
• Calixto Machado, "Brain death: a reappraisal", Springer, 2007, ISBN 0-387-38975-X, pp. 73–74