What is, and who is at risk for heat stroke?
Heat stroke is a form of hyperthermia or heat-related illness,
elevated body temperature
with accompanying physical symptoms including changes in the nervous system
Unlike heat cramps and heat exhaustion, two
other forms of hyperthermia
that are less severe,
heat stroke is a true
medical emergency that is often fatal if not properly and promptly treated.
Heat stroke is also sometimes referred to as heatstroke or sun stroke. Severe
hyperthermia is defined as a body temperature of 104 F (40 C) or higher.
The body normally generates heat as a result of
metabolism, and is usually able to dissipate the heat by radiation of heat through
the skin or by evaporation of sweat. However, in extreme heat, high humidity, or vigorous
physical exertion under the sun, the body may not be able to sufficiently dissipate the heat and the
body temperature rises, sometimes up to 106 F (41.1 C) or higher.
Another cause of heat stroke is
dehydration. A dehydrated person may not be able
to sweat fast enough to dissipate heat, which causes the body temperature to
Heat stroke is not the same as a stroke. "Stroke"
is the general term used to describe decreased oxygen flow to an area of the
Those most susceptible (at risk) individuals to heat stroke include:
- The elderly (often with associated heart diseases, lung diseases, kidney
diseases, or who are taking medications that make them vulnerable to
dehydration and heat strokes)
- Individuals who work outside and physically exert themselves under the
- Infants, children, or pets left in cars.
Heat stroke is sometimes classified as exertional heat stroke (EHS, which is
due to overexertion in hot weather) or non-exertional heat stroke (NEHS, which
occurs in climactic extremes and affects the elderly, infants, and chronically