Heat Stroke by Ray Sahelian, M.D.

Dehydration and heat stroke are two very common heat-related diseases that can be life-threatening if left untreated.

What is Heat Stroke?
Heat stroke is the most severe form of heat illness and is a life-threatening emergency. Heat stroke is the result of long, extreme exposure to the sun, in which a person does not sweat enough to lower body temperature. The elderly, infants, persons who work outdoors and those on certain types of medications are most susceptible to heat stroke. It is a condition that develops rapidly and requires immediate medical treatment.

What causes heat stroke?
Our bodies produce a tremendous amount of internal heat and we normally cool ourselves by sweating and radiating heat through the skin. However, in certain circumstances, such as extreme heat, high humidity or vigorous activity in the hot sun, this cooling system may begin to fail, allowing heat to build up to dangerous levels. If a person becomes dehydrated and can not sweat enough to cool their body, their internal temperature may rise to dangerously high levels, causing heat stroke.

Treatment for Heat Stroke

The best treatment for exertional heat stroke is whole-body cooling, such as immediate immersion in cold water. Athletes with heat exhaustion should be cooled in an air-conditioned area, lying down with their legs propped above their heart level, while undergoing heart rate, blood pressure and other medical monitoring.

Athletics and Heat Stroke

As temperatures soar during summer months, the National Athletic Trainers' Association (NATA) advises that athletes, parents, coaches and medical personnel follow their new recommendations for preventing and treating dehydration, heat stroke and other exertional heat illnesses. All athletes should be properly hydrated before they start any exercise session, according to a NATA statement, and all fluids should be replenished within no more than two hours after the exercise is completed. If signs of dehydration do appear, athletes should be moved to a cool environment and rehydrated, the NATA experts advise. Strenuous physical activity coupled with environmental heat stress can also lead to heat stroke, which is characterized by abnormalities in the central nervous system, or heat exhaustion, which describes the heart's inability to maintain a normal output. In both cases, an athlete may experience headache or dizziness. Those suffering from heat stroke may also be affected by seizures, confusion or other dysfunctions of the central nervous system, while athletes with heat exhaustion may lose coordination, sweat profusely, or experience stomach or intestinal cramps.

Heat Cramps

Athletes may experience heat cramps while performing intense exercise in the heat. Heat cramps may be alleviated once athletes are rehydrated and they consume sports drinks or other fluids to replace the sodium lost during exercise.

Caution with Overhydration

Excessively low sodium levels, which can occur when an individual is overhydrated, may ultimately result in fluid accumulating in the brain and/or lungs. Signs and symptoms include nausea, vomiting and swelling of hands and feet.