Working outside in hot humid weather increases the risk of heat related illnesses. All of these illnesses occur when the temperature is high and especially during periods of heavy exertion. Heat cramps can occur in the muscles that are being heavily used in the heat. Generally the body temperature is normal and sweating is normal or excessive.

Heat exhaustion, the most common of these problems, is a syndrome of fatigue, weakness and dizziness following exposure to high temperatures. The skin often appears grey, and can be cool and clammy. The person affected may be breathing rapidly and may have a rapid heartbeat. Nausea and the urge to defecate are common symptoms. Heat syncope is loss of consciousness with the symptoms of heat exhaustion. In these conditions the body temperature is normal.

Heat stroke, the most serious of these illnesses, comes in two forms. In both forms the body temperature is elevated, often greater than 105. Exertional heat stroke occurs in otherwise healthy individuals engaged in heavy exertion in the heat. Symptoms of heat exhaustion, as well as headache, vertigo, confusion, and abdominal distress may precede loss of consciousness. The patient usually continues to sweat. Classical heat stroke occurs in older and ill individuals during heat waves with similar symptoms but hot dry skin.

Heat cramps, exhaustion and syncope all respond to hydration and cooling. Sometimes IV fluids may be needed. Heat stroke is a serious medical emergency that can lead to death and disability and needs to be treated in the hospital. If there is any question, call the ambulance and do what you can to cool the affected individual while waiting for EMS to arrive.