Hyperthermia and hypothermia in the elderly.

Elderly populations are prone to both hyperthermia and hypothermia because of innate physiologic changes associated with aging, the presence of chronic disease, and the use of polypharmacy. Hyperthermia is a true medical emergency with a high mortality rate, requiring rapid cooling and aggressive supportive care. Hypothermia is a common finding in elderly persons. Patients should be warmed in the least aggressive manner that will adequately treat their clinical situation. Hypothermia due to underlying disease carries a high mortality rate, as does the onset of ventricular fibrillation.