Are you hot, sweaty and experiencing muscle spasms? It’s probably heat cramps. Your body loses important nutrients when you sweat, which can cause painful muscle tightening. Drinking something with electrolytes and cooling your body should help.
Heat cramps are painful muscle spasms that happen when your body gets too hot. They’re a mild form of heat illness and a sign of heat exhaustion. When you experience heat cramps, you may feel an uncomfortable tightening of the muscles in your:
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.
Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy
Heat cramps, heat exhaustion and heatstroke are all types of heat illness or hyperthermia. Heat cramps are a mild form of heat illness, and heatstroke is the most severe type. Heat cramps can turn into heat exhaustion or heatstroke if you:
Heat cramps are a sign that your body is overheated. Cool down and stay hydrated to avoid more serious heat-related illnesses.
Heatstroke requires emergency medical attention. If left untreated, heatstroke can cause permanent disability or death.
The main symptom of heat cramps is feeling your muscles tighten and harden. The pain can range from mild to severe. Sometimes, you can even see the muscle cramping. For example, if you’re experiencing heat cramps in your toes, you may see your toes curling or stiffening. And since heat cramps are involuntary, you can’t control your muscle as it spasms.
You may also have other symptoms of heat exhaustion, including:
Intense physical activity in a hot location can lead to heat cramps. The cause is a combination of your rising body temperature and a loss of electrolytes through sweat.
Heat cramps can affect anyone who’s active in the heat. Some people have a higher risk of experiencing muscle cramps from the heat — usually those who work in hot environments, like:
Certain groups of people are more affected by heat cramps and other heat-related illnesses. One study found that about 28,000 heat-related hospitalizations occurred between 2001 and 2010. Researchers noted that:
You can usually diagnose a heat cramp on your own. If you do intense physical activity in the heat and feel a muscle spasm, you most likely have a heat cramp.
If you see your healthcare provider for heat cramps, they’ll review your medical history and medications. During the exam, your provider may ask you:
To diagnose heat cramps, your healthcare provider needs to rule out other conditions like rhabdomyolysis, liver disease or kidney disease. They may use blood and urine tests to identify any underlying conditions.
In rare cases, providers may use an MRI (an imaging test) to see if your leg cramps are from neurological (nerve) problems.
You can treat your heat cramps yourself. The best way to soothe cramping muscles and relieve pain is to:
Eat foods and drink fluids that will replenish your body’s lost electrolytes, including:
Cooling down is the best thing you can do for your body when you have heat cramps. Stop what you’re doing and get out of the heat. Lower your body’s temperature and replenish the nutrients you lost from sweating. These steps help the heat cramps go away and can prevent heat exhaustion and heatstroke.
Some people are more susceptible to heat illnesses (like heat cramps) than others. If you’re at high risk, talk to your healthcare provider about how you can lower your risk, especially before doing activities in the heat. You may be at higher risk if you have:
The U.S. Centers for Disease Control and Prevention (CDC) ranks air-conditioning as the No. 1 protective factor against heat-related illness. The best way to prevent heat cramps is to avoid hot, humid areas, especially when you’re doing intense physical activity.
Some people can’t avoid being outside on hot days. If you know you’ll be sweating or in a hot environment, try to keep your body temperature from rising too quickly. Prepare in advance with these tips:
Infants, young children and people over age 65 have a higher risk of experiencing heat illnesses like heat cramps. To help protect these individuals, follow these recommendations:
If you have heat cramps, you can expect to feel some pain and discomfort in your muscle that’s tightening. The muscle spasms should go away after a few minutes, especially if you cool down your body’s temperature.
If you don’t keep a healthy balance of electrolytes in your body, the heat cramps will return. Stay hydrated with a sports drink and eat healthy snacks periodically, especially during intense activities that cause heavy sweating.
Heat cramps usually only last from a few seconds to 15 minutes. If yours last longer or are worrisome, talk to a healthcare provider.
You should recover quickly after treating your heat cramps. How long recovery takes depends on your age, physical condition and how quickly you relieve the pain from the muscle spasms.
See your provider if the heat cramps:
Go to the ER if you experience these symptoms:
A note from Cleveland Clinic
Heat cramps are uncomfortable and painful but typically don’t last long. These muscle spasms are a sign that your body is overheated and needs electrolytes. The most important thing to do is rest from whatever activity you’re doing and find a cool, shady spot. Drink a sports drink and have a snack. Massaging the sore muscle can help ease the pain. Once your body cools down and replenishes its electrolytes, you should feel better.
Last reviewed by a Cleveland Clinic medical professional on 03/31/2023.
Learn more about our editorial process.