Algor mortis

File:Postmortem interval changes (stages of death).png

Stages of death, including algor mortis.

File:Glaister equation.svg

The Glaister equation is used to estimate the time of death based on body temperature.

Algor mortis (Latin: "coldness of death") is the second stage of death, following pallor mortis and preceding rigor mortis. It refers to the reduction in body temperature following death. This process is a key factor in forensic science for estimating the postmortem interval (PMI), which is the time elapsed since death.

Mechanism

After death, the body's metabolic processes cease, and it no longer generates heat. As a result, the body begins to cool down to match the ambient temperature. The rate of cooling can be influenced by several factors, including the environment, clothing, and the body's initial temperature.

Estimation of Time of Death

The rate of cooling is often used to estimate the time of death. The Glaister equation is a formula used to approximate the time since death based on body temperature:

$\text{Time since death (hours)}=\frac{37-\text{rectal temperature (°C)}}{1.5}$

This equation assumes a linear cooling rate of approximately 1.5°C per hour under typical conditions. However, this rate can vary significantly based on external factors such as:

• Ambient temperature
• Humidity
• Air movement
• Body size and composition
• Clothing and coverings

Factors Affecting Algor Mortis

Several factors can affect the rate of algor mortis:

• Environmental Conditions: A body in a warm environment will cool more slowly than one in a cold environment.
• Clothing: Clothing can insulate the body and slow the cooling process.
• Body Composition: Fat acts as an insulator, so a body with more adipose tissue may cool more slowly.
• Air Movement: Increased air movement can enhance heat loss through convection.

Forensic Implications

Algor mortis is a crucial component in forensic investigations. By understanding the cooling process, forensic pathologists can provide a more accurate estimate of the time of death, which can be critical in criminal investigations.

Limitations

While algor mortis is a useful tool, it is not infallible. The variability in cooling rates due to external factors means that estimates of the time of death based solely on body temperature should be corroborated with other evidence, such as rigor mortis, livor mortis, and decomposition stages.

Also see

• Pallor mortis
• Rigor mortis
• Livor mortis
• Decomposition
• Forensic pathology