Forensics & autopsy
Types of injuries
Hypo- and hyperthermia
Author: Lindsey Harle, M.D.
Topic Completed: 1 August 2013
Minor changes: 26 August 2019
Copyright: (c) 2012-2019, PathologyOutlines.com, Inc.
PubMed search: Hypothermia [title] OR hyperthermia [title] forensic
Cite this page: Harle L. Hypo- and hyperthermia. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/forensicshypohyperthermia.html. Accessed August 11th, 2020.
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
