Heat Stroke

Heat stroke occurs when heat gain overwhelms the body's ability to dissipate heat. Core temperature rises, sweating and other heat-loss mechanisms fail, and cellular proteins begin to malfunction. Endothelial injury, systemic inflammation, and coagulation activation then impair the brain, liver, kidneys, skeletal muscle, lungs, and clotting system. The defining clinical pair is marked hyperthermia plus central nervous system dysfunction. Confusion, agitation, slurred speech, irritability, ataxia, delirium, seizure, collapse, or loss of consciousness in a hot environment should be treated as heat stroke until another cause is established. Do not wait for a perfect temperature reading before activating emergency care. Two patterns are recognized: - Classic, or non-exertional, heat stroke usually develops during an environmental heat event in older adults, infants, people with chronic illness, people taking heat-sensitive medications, or people who are isolated or unable to access cooling. Skin is often hot and dry, but this is not universal. - Exertional heat stroke develops rapidly during strenuous activity, heavy work, or training. Sweating is frequently still present because sweat production may continue even while thermoregulation is failing. A damp shirt...