What is the root cause of heat stroke?

Heatstroke is a condition in which the body becomes overheated in a relatively short space of time. It can be a life threatening condition, requiring urgent medical attention.

Abnormally high body temperatures or hyperthermia, may occur in several different circumstances, such as:

* classic heatstroke (also called sunstroke: a little misleading because the condition can arise without the direct effect of the sun) when, typically, the skin is flushed, red and dry.

heatstroke caused by exertion, which often occurs in conjunction with pronounced physical exertion, eg sports activity.

in extensive burns (including sunburn), where the sweat glands have been damaged or destroyed.

in a number of less common medical conditions, such as overactivity of the thyroid gland.