Heat cramps are painful muscle spasms that can happen during activity in hot environments. People who sweat a lot may be prone to heat cramps. That's because the fluid and electrolyte loss that occurs through sweating often contributes to heat cramps.
Heat cramps most often affect the muscles of the calves, arms, abdomen and back. But heat cramps may happen to any muscle group involved in exercise.
If you suspect heat cramps:
Call your healthcare professional if your heat cramps don't go away within one hour. You should also seek medical attention if you have heart problems or are on a low-sodium diet.