Table 1. Signs and symptoms of heat exhaustion, classical and exertional heat stroke. Heat exhaustion Classical heat stroke Exertional heat stroke Fatigue and weakness Tachycardia Anxiety Muscle cramps Headache Irritability Vertigo Syncope Prolific sweating Hypotension Nausea Cold, pale, clammy skin Chills Piloerection Mental deterioration As with heat exhaustion and: Cessation of sweating Hot and dry skin Seizures Loss of consciousness Death As with heat exhaustion and: Continuation of sweating Incoherent speech Acute renal failure Lactic acidosis Rhabdomyolysis Hyperuricemia Hyperkalemia Seizures Loss of consciousness Death