Heat emergencies.

Heat emergencies occur when the body is unable to adequately dissipate heat. Hyperthermic patients should be cooled immediately with a lukewarm-water spray and cool moving air. Patients with heat exhaustion respond well to administration of intravenous fluids. Patients with heatstroke have a complete loss of thermoregulation, a core temperature greater than 40.5 degrees C (105 degrees F) and impaired mental status. These critically ill patients must be cooled quickly to 39 degrees C (102 degrees F) to avoid devastating complications. Intensive care monitoring and support are indicated. To reduce the risk of heat injury in hot weather, frail and elderly persons must maintain hydration and may need to consider alternate living arrangements. Laborers, athletes and military personnel benefit from gradual acclimation to the heat, increased fluid intake, vapor-permeable clothing and frequent rest periods.