A potentially fatal condition, characterized by the failure of the body's heat-regulating mechanisms, is:

It is Heat stroke. This is a form of hyperthermia in which the body temperature is elevated dramatically. It is a medical emergency and can be fatal if not promptly and properly treated. It is caused by an elevation in body temperature, often accompanied by dehydration. The symptoms include; confusion, the absence of sweating, agitation, disorientation, and coma. Most important measures to prevent heat stroke is to avoid becoming dehydrated and to avoid vigorous physical activities in hot and humid weather.