Hyperthermia

Elevated body temperature due to failed thermoregulation

Hyperthermia, also known as overheating, is a condition in which an individual's body temperature is elevated beyond normal due to failed thermoregulation. The person's body produces or absorbs more heat than it dissipates. According to the International Emergency Medicine Education Project, severe hyperthermia (body temperature elevation of beyond 40 °C (104 °F)) "becomes a medical emergency requiring immediate treatment to prevent disability or death".

From Wikipedia, under CC BY-SA. More on occurri.