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Monday 23 March 2009

Hyperthermia, in its advanced state referred to as heat stroke or sunstroke, is an acute condition which occurs when the body produces or absorbs more heat than it can dissipate. It is usually caused by prolonged exposure to high temperatures.

The heat-regulating mechanisms of the body eventually become overwhelmed and unable to effectively deal with the heat, causing the body temperature to climb uncontrollably. Hyperthermia is a medical emergency which requires immediate treatment.

Hyperthermia can be created artificially by drugs or medical devices. In these instances it may be used to treat cancer and other conditions. A malignant hyperthermia is a rare complication of some types of general anesthesia.


Prolonged exposure to elevated ambient temperatures can result in heat cramps, heat exhaustion, and heat stroke.

- Heat cramps result from loss of electrolytes through sweating. Cramping of voluntary muscles, usually in association with vigorous exercise, is the hallmark. Heat-dissipating mechanisms are able to maintain normal core body temperature.

- Heat exhaustion is probably the most common heat syndrome. Its onset is sudden, with prostration and collapse, and it results from a failure of the cardiovascular system to compensate for hypovolemia, secondary to water depletion. After a period of collapse, which is usually brief, equilibrium is spontaneously re-established.

See also

- heat stroke