What Are Heat Cramps?

Heat cramps are painful muscles spasms that occur in the arms, legs, or abdomen that usually occur after several hours of exertion in the heat. In addition to muscle cramps, other symptoms of heat cramps may include faintness, dizziness, weakness, and excessive sweating.

Causes

The exact cause of heat cramps is unknown, but the theories most commonly cited include:

• Altered neuromuscular control
• Dehydration
• Electrolyte depletion
• Poor conditioning
• Muscle fatigue
• Doing a new activity

Muscle cramps are more common during exercise in the heat because sweat contains fluids as well as electrolytes (salt, potassium, magnesium, and calcium). When these nutrients, particularly sodium, fall to certain levels due to excessive sweating, the incidence of heat cramps increase.

To preventheatcrampsin a hot environment, workers should drink about a cup of either water or electrolyte solution every 20 minutes. Once someone has heatcramps, clear juice or an electrolyte solution can help alleviate them.                      

Stop activity, and sit quietly in a cool place. Drink a sports beverage with electrolytes (you can makeyour own sodium-based solution with 1/4 teaspoon table salt mixed in a quart of water). Gently stretch and massage the cramping muscle. Hold the joint in a stretched position until the cramp stops. Seek medical treatment if crampspersist for an hour or more.