Complications of heat exhaustion include nausea, vomiting, dehydration and muscle weakness. If the activity is not stopped and the person left in a hot environment, there can be progression of symptoms to heat stroke, a life threatening emergency.

Heat stroke is a medical emergency and can be fatal if not promptly and properly treated. The cause of heat stroke is an elevation in body temperature, often accompanied by dehydration. Heat stroke is diagnosed by observation of the symptoms and signs in a person exposed to extreme temperatures.

Heatstroke is a medical emergency. Even with immediate treatment, it can be life-threatening or result in serious, long-term complications.