Algor Mortis
Definition
Postmortem cooling of the body toward ambient temperature, approximately 1-1.5 degrees Celsius per hour under average conditions. Used alongside other postmortem changes to narrow the postmortem interval, though influenced heavily by environment and body habitus.
- Cooling rate (early hours)
- approximately 0.7-1.5°C per hour
- Temperature target
- ambient (surrounding environment)
- Physical law
- Newton's law of cooling
- Used in PMI estimates
- Henssge nomogram and Marshall-Hoare calculations
Common questions
How much does body temperature drop after death?+
The body typically cools at a rate of roughly 0.7 to 1.5 degrees Celsius per hour in the early post-mortem period, depending on environmental conditions and body composition. This cooling follows Newton's law of cooling as the core temperature gradually approaches the ambient temperature.
Why do death investigators measure body cooling?+
Algor mortis is one of the primary post-mortem changes used to estimate the time since death. The Henssge nomogram and Marshall-Hoare calculations rely on algor mortis data alongside other factors like environmental temperature and body size to narrow down the post-mortem interval.
Does the cooling rate stay the same throughout?+
No. The early post-mortem period shows the most consistent cooling rate, but the pace is influenced heavily by the environment (ambient temperature, air movement, moisture), body size, clothing, and other factors. This variability is why algor mortis alone cannot pinpoint time of death precisely.
Related terms
- Adipocere
- A waxy, soap-like substance formed by saponification of body fat under anaerobic, wet, cool-to-moderate conditions. Replaces unsaturated fatty acids with saturated palmitic...
- Henssge Nomogram
- A graphical method using rectal temperature, ambient temperature and body weight to estimate PMI within a 95 percent confidence interval, with correction...
- Livor Mortis
- Postmortem pooling of blood in dependent tissues producing a purple-red discolouration. Becomes fixed at roughly 8-12 hours; discordance between liver position and...
- Post-Mortem Interval (PMI)
- The time elapsed between death and discovery or examination of remains. PMI estimation draws on multiple disciplines: soft tissue decomposition stage, insect...
- Rigor Mortis
- The post-mortem stiffening of muscle from ATP depletion and actin-myosin cross-linking. Develops over hours, peaks, and resolves with putrefaction.
- Autopsy
- Systematic external and internal examination of a dead body to find cause, manner and time of death. Ordered under BNSS 2023 Section...
- Bichat's Trio
- The three modes of death: coma (cerebral failure), asphyxia (respiratory failure), syncope (cardiac/circulatory failure). Named after Xavier Bichat, 1800.
- Brain Death
- Irreversible cessation of all functions of the entire brain, including the brainstem. Defined under Harvard criteria 1968 and adopted in India under...
- Cadaveric Spasm
- Instantaneous rigor without a flaccid phase, locking the muscle group active at death (clutched weapon, grass).
- Cellular Death
- Progressive death of individual cells after somatic death; different tissues die at different rates (cornea minutes, nerve cells hours, fibroblasts up to...
- Coroner Model
- A death-inquiry system headed by an elected or appointed official (the coroner) who need not be a physician. Holds legal authority to...
- Decomposition
- Autolysis (intracellular enzymes) plus putrefaction (bacterial breakdown). Greenish discoloration starts over the right iliac fossa.
Explained in these topics
- Time Since Death: PMI, Henssge Nomogram, Tropical CorrectionThe cooling of the body after death from core temperature toward ambient. The basis of Henssge and Marshall-Hoare PMI calculations.
- The Forensic Nurse Death Investigator and Coroner RolePostmortem cooling of the body toward ambient temperature, approximately 1-1.5 degrees Celsius per hour under average conditions. Used alongside other postmort...
- Post-Mortem Examination, Post-Mortem Changes and Time Since DeathPost-mortem cooling, roughly 0.7 to 1 degree C per hour in the first few hours under temperate Indian conditions.
- Thanatology: Death, Causes, Signs and Post-Mortem ChangesPost-mortem cooling of the body to the ambient temperature, following Newton's law of cooling with typical early rate of 1°C per hour.