Heat stroke is a life-threatening form of hyperthermia. It occurs when the body is overwhelmed by heat and unable to control its temperature.

Signs and symptoms of heat stroke include:

* A significant increase in body temperature
* Changes in mental status (like confusion or combativeness)
* Strong rapid pulse
* Lack of sweating
* Dry flushed skin feeling faint
* Staggering or coma.

Seek immediate emergency medical attention for a person with heat stroke symptoms, especially an older adult.