Heat Cramps

The mechanism of heat cramps is unknown but they can be caused by dehydration or lack of adequate electrolytes in the diet. Although muscle cramping is not a cause of sudden death, it can be confused with a more serious condition, exertional sickling (cramps with no palpable muscle contraction).

Heat cramps are painful involuntary cramping often in the legs, arms, or abdomen with muscle contraction that can easily felt. Heat cramps usually occur in the preseason conditioning phase when the body is not properly conditioned and more subject to fatigue. Heat cramps can easily be treated with rest, stretching the muscle, and rehydration of fluid and electrolytes.

How do you prevent heat cramps?

It may be impossible to completely prevent a cramp from occurring, however, certain factors can be modified in order to reduce the incidence of future heat cramps.

The most effective ways to prevent heat cramping in athletes include:

  • Acclimatizing the athlete to warm/hot environments if their sports require exercise in hot environmental conditions can help prevent heat cramps. Heat acclimatization protocols can be found here.
  • Similar to heat acclimation, acclimating to exercise by gradually progressing intensity and duration before requiring the athlete to perform all out in an event or extensive workout session healp prevent heat cramps. This process may also help prevent athletic injuries!
  • Educating athletes to replace fluids and salt lost in their sweat. This can be done by calculating whole body sweat loss during exercise using this sweat loss equation. Each athlete slightly differs in the amount of sweat and salt losses during exercise. Also keep in mind that these factors change depending on the temperature and humidy of the ambient environments, so sweat testing should be specific to the conditions in which the athletes are exercising.
  • Maintain a balanced electrolyte level by consuming electrolyte rich drinks before and during the athletic event or practice session if physical activity lasts longer than one hour in duration. Certain individuals naturally expel more sodium in their sweat compared to the average individual. These people may need supplemental/extra sodium in their diet.
    Removing excess clothing during physical activity may help reduce the chance of getting heat cramps by allowing for greater evaporation, keeping core body temperature lower during exercise. For example, if a field hockey goalie is performing conditioning drills during which protective equipment is unneccessary, the athlete should remove the equipment during this portion of the conditioning session.

What puts an individual at risk for heat cramps?

Exercise in heat when the individual is not accustomed to exercising in the hot conditions

  • Profuse sweating or body water loss during exercise. These athletes lose a considerable amount of electrolytes through their sweat which predisposes them to heat cramping
  • Exercising for an extended duration of time or participating in multiple practice sessions per day without replenishing the salts and water lost during sweating
  • Muscular fatigue
  • Wearing additional layers of clothing, protective gear, or equipment

Look for these symptoms in athletes when heat cramps are suspected:

  • Dehydration, thirst, sweating, transient (short term) muscle cramps, and fatigue
  • Painful, involuntary muscle spasms (usually occurring in the legs) associated with exercise in the heat when athletes have been sweating profusely
  • A precursor to the initial onset of cramps involves muscle twitches or fasciculations. If this occurs, remove the athlete from the heat and encourage rehydration with an electrolyte beverage
  • Heat emergencies or illnesses are caused by exposure to extreme heat and sun. Heat illnesses can be prevented by being careful in hot, humid weather.


Heat injuries can occur due to high temperatures and humidity. You are more likely to feel the effects of heat sooner if:

  • You are not used to high temperatures or high humidity
  • You are a child or an older adult
  • You are already ill from another cause or have been injured.
  • You are obese
  • You are also exercising (even a person who is in good shape can suffer heat illness if warning signs are ignored)

The following make it harder for the body to regulate the temperature, and make a heat emergency more likely:

  • Drinking alcohol before or during exposure to heat or high humidity
  • Not drinking enough fluids when you’re active on warmer or hot days
  • Heart disease
  • Certain medicines: Examples are beta blockers, water pills or diuretics, some medicines used to treat depression, psychosis, or ADHD
  • Sweat gland problems
  • Wearing too much clothing


Heat cramps are the first stage of heat illness. If these symptoms are not treated, it can lead to heat exhaustion and then heatstroke.

Heat stroke occurs when the body is no longer able to regulate the temperature, and it keeps rising. Heatstroke can cause shock, brain damage, organ failure, and even death.

The early symptoms of heat cramps include:

  • Muscle cramps and pains, that most often occur in the legs or abdomen
  • Very heavy sweating
  • Fatigue
  • Thirst

Later symptoms of heat exhaustion include:

  • Headache
  • Dizziness and light-headedness
  • Weakness
  • Nausea and vomiting
  • Cool, moist skin
  • Dark urine

The symptoms of heatstroke include (call 911 or the local emergency number right away):

  • Fever (temperature above 104 °F)
  • Irrational behavior
  • Extreme confusion
  • Dry, hot, and red skin
  • Rapid, shallow breathing
  • Rapid, weak pulse
  • Seizures
  • Unconsciousness

First Aid

If you think a person may have heat illness or emergency:

  • Have the person lie down in a cool place. Raise the person’s feet about 12 inches.
  • Apply cool, wet cloths (or cool water directly) to the person’s skin and use a fan to lower body temperature. Place cold compresses on the person’s neck, groin, and armpits.
  • If alert, give the person a beverage to sip (such as a sports drink), or make a salted drink by adding a teaspoon of salt per quart of water. Give a half cup every 15 minutes. Cool water will do if salt beverages are not available.
  • For muscle cramps, give beverages as noted above and massage affected muscles gently, but firmly, until they relax.\
  • If the person shows signs of shock (bluish lips and fingernails and decreased alertness), starts having seizures, or loses consciousness, call 911 and give first aid as needed.


  • Do NOT give the person medications that are used to treat fever (such as aspirin or acetaminophen). They will not help, and they may be harmful.
    Do NOT give the person salt tablets without mixing the salt with water.
    Do NOT give the person liquids that contain alcohol or caffeine. They will make it harder for the body to control its internal temperature.
    Do NOT use alcohol rubs on the person’s skin.
    Do NOT give the person anything by mouth (not even salted drinks) if the person is vomiting or unconscious.

Source and More Info: UCONN and MedlinePlus



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