Heat Cramps

When to See a Healthcare Provider

If your heat cramps do not improve within an hour of treatment or if your symptoms worsen (headache, dizziness, vomiting and nausea, fainting or a high temperature that’s greater than 104 degrees), seek immediate medical attention.

People who are on a low-sodium diet or who have heart problems should seek medical attention whenever they develop heat cramps.

In severe cases, your healthcare provider will quickly assess your symptoms, take a medical history, and determine the appropriate amount of intravenous (IV) fluids to treat your condition. Adequate rest is also essential to make a full recovery.

Heat Cramps

Complications of Heat Illness

If you have developed a heat-related illness, you may experience serious health complications that require immediate medical attention.

Potential complications of heat-related illness include:

  • Light-headedness or fainting (syncope) can occur if you are severely dehydrated or if there is reduced blood flow to the brain
  • Rhabdomyolysis (the breakdown of skeletal muscle) produces dark, tea-colored urine from an increase in myoglobin (muscle protein) release. Symptoms can include irregular heartbeat, muscle pain, vomiting, and kidney failure.
  • Acute liver failure is a rare condition in which your liver loses its ability to work properly by removing waste products from your blood. When the liver does not function as it should, your risk of developing bacterial or fungal infections that can lead to death increases.
  • Cardiac arrhythmias are conditions in which the heart beats either too fast (tachycardia), too slowly (bradycardia), or with an abnormal pattern or rhythm.
  • Coma is an extended period of unconsciousness.
Heat Cramps


It is easier to prevent heat illness than to treat it once symptoms develop. To minimize your risk of developing heat cramps, it’s important to stay hydrated.

Do not drink alcohol or beverages with caffeine before exercising since they increase the rate of dehydration. Drink plenty of fluids before and during exercise and replace lost electrolytes such as sodium, potassium, and magnesium with food or a sports drink.

Staying hydrated helps, but it’s also important to guard against overheating:

  • Avoid exercising or working during the hottest time of day: If you regularly exercise, do so closer to sunrise or sunset, especially during the summer.
  • Acclimatize to heat: If you are going to exercise in hot weather, acclimate to the heat for about a week before starting intense exercise.
  • Wear loose, light-colored clothing: Clothing that is lightweight and fits loosely is recommended. You can also invest in clothes that wick moisture from your skin to the outer layer of the clothing, where it can evaporate more easily. Brands like COOLMAX, Drymax, Smartwool, and polypropylene all have this property.
Heat Cramps


In general, treatments for heat cramps can be managed at home. They include:

  • Find a cool place and rest: Move to a cool place indoors and rest. Temporarily stop all strenuous physical work or exercise outdoors, especially during the summer when temperatures are high. Do not start further activity until the cramps have gone away.
  • Replenish fluid and electrolytes: Drink plenty of water and sports drinks or rehydration drinks that also replenish electrolytes. Eating potassium- or magnesium-rich foods may also help. These include bananas, sweet potatoes, beans/legumes, and avocados.
  • Elevate the legs: Lie down and prop your legs up.
  • Stretch and massage cramped muscles: Simple exercises can help relieve muscle fibers. Stretch or rub tense muscles slowly and gently to relieve uncontrollable muscle contractions and reduce pain. Regularly stretching cramped muscles can also prevent new ones from developing.
Heat Cramps

What Is Heat Exhaustion?

Heat exhaustion is a serious condition characterized by heat cramps, muscle weakness, headache, dizziness, nausea and vomiting, and even fainting. If left untreated, heat exhaustion can develop into a fatal heat stroke, in which the core body temperature reaches over 104 degrees.

Heat Cramps


Heat cramps typically develop after exercise or other strenuous physical activity rather than from just being at rest in the heat. They can occur with exercise even if the temperature is mild or even cool.

Heat cramps are the mildest form of heat-related illnesses, which also include heat exhaustion and heatstroke. Heat-related illnesses can be classified as mild or severe. Common symptoms of heat cramps include:

  • Heavy sweating (during intense exercise or prolonged exposure to high heat)
  • Muscle pain or spasms (especially in the legs)
  • Flushed, moist skin

If a person ceases activity, heat cramps usually start to improve within 30 minutes to an hour, sometimes longer. They may also come and go intermittently.

In some cases, heat cramps lead to severe heat-related illnesses, such as heat exhaustion and heatstroke. Heat exhaustion occurs when there is a significant loss of fluid and electrolytes due to prolonged exposure to extreme heat.

If heat exhaustion is left untreated, it can result in heatstroke, which is a potentially fatal condition that occurs when your internal body temperature reaches over 104 degrees.

Heat Cramps

Prevention and Treatment of Heat Cramps

Heat cramps are painful, brief muscle spasms that occur with exercise or strenuous work, especially in a hot environment. Cramps are felt in the muscles of the legs, arms, back, or abdomen that are fatigued by heavy work.

These cramps result from a loss of fluid (dehydration) and electrolytes (essential minerals, such as sodium, potassium, calcium, and magnesium) from excessive sweating. Other factors may contribute, such as fatigue and changes in how the nerves control muscles.

When you sweat during intense workouts and in high temperatures, your body loses nutrients in the form of electrolytes. Sweat contains a large amount of sodium and other nutrients that help regulate muscle contractions.

If these nutrients are lost more quickly than they are replenished, cramps can result. Cramping is one of the first signs your body can’t handle the heat.

This article discusses the symptoms, treatment, and prevention of heat cramps.

Heat Cramps