Forensic pathology
Types of injuries
Hypo- and hyperthermia

Author: Lindsey Harle, M.D. (see Authors page)

Revised: 12 January 2017, last major update August 2012

Copyright: (c) 2012-2017, PathologyOutlines.com, Inc.

PubMed search: hypothermia [title] OR hyperthermia [title] forensic

Cite this page: Hypo- and hyperthermia. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/forensicshypohyperthermia.html. Accessed August 16th, 2017.
Hypothermia
  • Core body temperature below 95°F (35°C)
  • Usually due to environmental exposure
  • Increased risk in very young and very old, thin individuals, males (due to decreased subcutaneous fat)
  • Cold water exposure more rapidly fatal than cold air exposure, because water rapidly dissipates heat

Physiological response to cold exposure:
  • Superficial vasoconstriction
  • Shivering
  • Increased cellular metabolism (to produce heat); more efficient in infants due to "brown fat"
  • When compensatory mechanisms fail, body temperature falls linearly

Autopsy findings:
  • No specific findings in hypothermia; it is a diagnosis of exclusion
  • Cherry red lividity: due to accumulation of oxyhemoglobin in tissues; nonspecific (also seen in CO poisoning)
  • If individual survives for a period of time, may show hemorrhagic pancreatitis, mucosal ulceration of GI tract, pneumonia, acute tubular necrosis, cardiomyocyte necrosis
  • Paradoxical undressing: terminal hallucinations lead the individual to feel overheated despite the cold environment, causing them to undress
Hyperthermia
  • Core body temperature above 105°F (40.5°C)
  • Heat stroke is severe form
  • Occurs when body's mechanisms of dissipating heat are overwhelmed
  • Risk factors: alcoholism, atherosclerosis, obesity, certain drugs (tricyclic antidepressants, some tranquilizers, monoamine oxidase inhibitors)
  • Symptoms: hyperthermia, hot and dry skin, CNS dysfunction
  • Vasodilation occurs, leading to circulatory failure
  • If individual survives for a period of time, may develop pneumonia, acute tubular necrosis, adrenal hemorrhage, liver and myocardial necrosis, and DIC
  • Autopsy findings: nonspecific; diagnosis is made based on scene investigation and antemortem signs and symptoms

More mild forms include heat cramps and heat exhaustion:
  • Heat cramps: due to salt depletion; skin is moist and cool, body temperature is normal
  • Heat exhaustion: due to salt and water depletion; headache, nausea / vomiting, dizziness, weakness, cramps; body temperature is normal or slightly elevated