Heat cramps are painful muscle spasms that occur due to dehydration and loss of nutrients from excessive sweating. They are one of the first stages of heat illness and are associated with heavy perspiration. Heat cramps are most common in the abdomen, back, arms, or legs. They are a mild form of heat illness and a sign of heat exhaustion. When you sweat a lot, your body loses salt and nutrients (electrolytes) in the sweat. Drinking large amounts of water quickly helps hydrate you, but it also dilutes the nutrients in your body. That can cause your muscles to tighten and cramp.

Heat cramps can be prevented by staying hydrated with water and electrolyte drinks, such as Gatorade, which replenish sodium, potassium, and other electrolytes that are lost due to sweat. It is also important to take breaks from exercise more often and avoid hot temperatures, especially for children, elderly, and obese individuals who are the most susceptible to heat cramps.

If you develop heat cramps, it is important to get out of the heat and cool down. Rest in a well-ventilated or air-conditioned area, drink water and an electrolyte beverage, and consume water frequently over the next few hours. You can also make your own salted drink to replenish lost nutrients by combining one teaspoon of salt with a quart of water. Massaging the sore muscle can help ease the pain. Heat cramps are uncomfortable and painful but typically don’t last long. However, if heat cramps are not treated, they can progress to heat exhaustion or heatstroke, which are more serious heat-related illnesses.