Definition

Heat disorders are a group of illnesses caused by prolonged exposure to hot temperatures, restricted fluid intake, or failure of the body's ability to regulate its temperature. The general term used for heat disorders is hyperthermia (pronounced hi-per-THUR-mee-uh). The three most common forms of hyperthermia are heat exhaustion, heat stroke, and heat cramps.

Description

Hyperthermia can cause harm to people of all ages. But its effects are more serious with increasing age. The conditions that cause heat cramps in a teenager may cause a more serious form of hyperthermia—heat exhaustion—in a middle-aged person. Those same conditions may cause even more serious effects in an older person, a form of hyperthermia known as heat stroke.

The human body functions normally only within a very narrow range of temperatures close to 98.6°F (37°C). If the body gets much warmer or much colder than 98.6°F, health...