Heat cramps: Painful muscle spasms in the abdomen, arms, or legs following strenuous activity. The skin is usually moist and cool and the pulse is normal or slightly raised. Body temperature is mostly normal. Heat cramps often are caused by a lack of salt in the body, but salt replacement should not be considered without advice from a physician. Heat cramps usually affect people who sweat a lot during strenuous activity. The sweating depletes the body's salt and moisture. The low salt level in the muscles causes painful cramps. Heat cramps may also be a symptom of heat exhaustion.
If you have heart problems or are on a low sodium diet, get medical attention for heat cramps. If medical attention is not necessary, take these steps: