A. Heat cramps are sudden, painful cramps or spasms, possibly causing muscles to jerk involuntarily. Heat cramps primarily affect the arms, legs, and/or stomach. Because heat cramps usually involve tired muscles, runners often have cramping in the calves, quadriceps, and abdominal muscles.
Alone they are not dangerous, but are a sign of worse things to come. Ignoring heat cramps often leads to heat exhaustion.
