Wednesday 25 March 2009
Heat stroke is associated with high ambient temperatures and high humidity. Thermoregulatory mechanisms fail, sweating ceases, and core body temperature rises. Body temperatures of 112° to 113°F have been recorded in some terminal cases. Clinically, a rectal temperature of 106°F or higher is considered a grave prognostic sign, and the mortality rate for such patients exceeds 50%.
The underlying mechanism is marked generalized peripheral vasodilation with peripheral pooling of blood and a decreased effective circulating blood volume.
Elderly persons, individuals undergoing intense physical stress (including young athletes and military recruits), and persons with cardiovascular disease are prime candidates for heat stroke.