While heat stroke and heat exhaustion share certain symptoms, those unique to heat stroke include increased body temperature, delirium, convulsions and a rapid heart rate, according to WebMD. Heat stroke often occurs suddenly and can occur without any preliminary symptoms of heat exhaustion such as fatigue, nausea or dizziness.
While heat stroke and heat exhaustion are related conditions, heat stroke is significantly more dangerous and can be fatal if not immediately and comprehensively treated, explains WebMD. Symptoms shared by both conditions include nausea, fatigue, confusion, dizziness and fainting.
One of the most effective ways to tell the difference between the two conditions is through the sweat of the affected individual. Individuals suffering from heat exhaustion typically experience drenching sweats accompanied by clammy, cold skin, while individuals suffering from heat stroke sweat less than usual and typically have skin that is flushed, hot and dry to the touch, notes WebMD.
Another important determining factor is the heartbeat of the affected individual, according to WebMD. A rapid heart rate is a symptom of heat stroke, while individuals suffering from heat exhaustion typically exhibit weakened or slowed heartbeats. Both conditions require immediate medical attention, especially if the condition of the affected individual does not improve when placed in a cool area and administered salts and fluids.