A heat cramp consists of spasmodic muscle pain typically associated with exercise and physical exertion in, but not limited to, hot environment. Individuals that are most susceptible to cramping include athletes, miners, and military personnel. Heat cramps occur as a result of excessive sweating, thus loss of water and sodium occur, with little or no replacement of sodium, or both sodium and water [1] [2]. This leads to hyponatremia. Cramps may start abruptly and last from several minutes to hours. The muscles in the limbs are usually affected.

Heat cramps are distinguished from cramps due to muscle fatigue by their unresponsiveness to measures such as stretching and cooling, as well as more severe pain [3] [4] [5]. The mechanism by which these cramps occur is thought to be a contraction of the extracellular compartment, which concentrates neurotransmitters and ions, leading to hyper-excitable nerve terminals. They usually affect alternating groups of voluntary muscle, resulting in the perception of what is sometimes described as a 'wandering' cramp. Some patients may experience prodromal muscle twitching shortly before the full onset of cramps. As an episode of cramping continues, it becomes more widespread, involving a greater number of muscles. Heat cramps may be seen as a form of heat illness; some literature suggests that the former may be considered as one of the symptoms of heat exhaustion.

Heat cramps in certain occupations have been successfully treated by drinking saline. Similarly, athletes can use this method to avoid cramping [6]. The same protective effect is not achieved with hydration alone. This provides further evidence that the heat cramps occur due to loss of sodium in sweat. Resting and decreasing physical activity at the first signs of cramping can also prevent heat cramps [7].

• Severe Pain

  Heat cramps are distinguished from cramps due to muscle fatigue by their unresponsiveness to measures such as stretching and cooling, as well as more severe pain. [symptoma.com]

  Severe pain and carpopedal spasm may incapacitate the hands and feet. Temperature is normal, and other findings are unremarkable. The cramp usually lasts minutes to hours. Diagnosis is by history and clinical evaluation. [merckmanuals.com]

  Symptoms include cramping of the muscles that comes on suddenly and causes severe pain. Cramping may last from minutes to hours. [fairview.org]

  What's happened is that your muscle has tightened and shortened, causing sudden, severe pain, explains Debra Zillmer, MD, orthopedic surgeon and medical director of the Gundersen Lutheran Sports Medicine Clinic in La Crosse, WI. [prevention.com]

• Increased Sweating

  It can also be a sign of low sodium, due to increase sweating in the hot weather. [sharecare.com]

  Symptoms can include: increased thirst weakness fainting muscle cramps nausea and/or vomiting irritability headache increase sweating cool, clammy skin elevation of body temperature, but less than 104°F (40°C) What to Do: Bring your child to a cooler [kidshealth.org]

  Acclimatization to hot environments usually occurs over 7-10 days and enables individuals to reduce the threshold at which sweating begins, increase sweat production, and increase the capacity of the sweat glands to reabsorb sweat sodium, thereby increasing [emedicine.medscape.com]

• Muscle Cramp

  Preventing Muscle Cramps Until we learn the exact cause of muscle cramps, it will be difficult to say with any confidence how to prevent them. [sportsmedicine.about.com]

  Muscle cramps rarely occur in a strong and rested muscle. Cramps invariably become a factor in athletic performance after the muscle has endured significant stress. [faqs.org]

  Barely detectable muscle fasciculations or "twitches" in the affected muscles can rapidly progress to debilitating muscle cramps in just 20 to 30 minutes. [ncbi.nlm.nih.gov]

• Muscle Twitch

  Heat cramps are muscle twitches or spasms, usually in the abdomen, arms, or legs that are associated with heat and dehydration. Sweating depletes the body of water and salt. [sharecare.com]

  They usually affect alternating groups of voluntary muscle, resulting in the perception of what is sometimes described as a 'wandering' cramp. Some patients may experience prodromal muscle twitching shortly before the full onset of cramps. [symptoma.com]

  That spontaneous discharge is a muscle twitch, which can lead to a muscle cramp. By maintaining proper hydration, you can prevent dramatic shifts in fluids that contribute to abnormal muscle contractions. [active.com]

  […] 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 [ksi.uconn.edu]

• Myalgia

  Shock DIC TABLE 3 Signs and Symptoms of Potentially Life-Threatening Heat-Related Illnesses Heat cramps Elevated body temperature Thirst Muscle cramps Sweating Tachycardia Heat exhaustion Same as heat cramps, plus : Nausea/vomiting Headache Malaise/myalgias [aafp.org]

The diagnosis is based on the clinical signs and symptoms, as well as the history surrounding the occurrence of the heat cramp. Other tests that may be carried out include:

• Urea and electrolytes: Results often show normal or high sodium levels. This should not be misinterpreted to mean that plasma sodium is present in adequate amounts. On the contrary, it is a result of the body's compensatory mechanisms, in which it tries to keep the extracellular environment constant despite losses through sweat.
• 24-hour urine collection: This may be useful in predicting the likelihood of an individual suffering from future cramps, especially if the kidneys' excretion of sodium in the urine is reduced.
• Electromyography: This test proves that heat cramps are disorganized over-activity of nerve endings and muscle, as a result of a shrunken extracellular compartment and low sodium. It does so by the positive findings of abnormal electrical activity and fasciculations [8].

• Hyponatremia

  This leads to hyponatremia. Cramps may start abruptly and last from several minutes to hours. The muscles in the limbs are usually affected. [symptoma.com]

  Replacement of water without sodium can lead to dangerously low blood sodium levels, called hyponatremia. Hyponatremia will also occur if you are sweating a lot and simply losing a lot of sodium in sweat. [active.com]

  In contrast, heat cramps can occur in physically fit people who sweat profusely and replace lost water but not salt, thereby causing hyponatremia. [merckmanuals.com]

  Pathophysiology Hyponatremia and volume depletion from profuse sweating Provoked by muscle overload or Fatigue, dehydration or electrolyte disturbance IV. [fpnotebook.com]

Without adequate treatment, this can lead to heat stroke. Heat cramps manifest as sporadic and spontaneous muscle cramps and spasms. They can occur during or after an intense workout. [theydiffer.com]

[…] applied to the affected muscle Drink one quart of water with one teaspoon of salt Drink some clear juice / electrolyte-containing sports drink Practice gentle stretching exercise of the affected muscle Seek medical help if the cramps remain after 1 hour Prognosis [medindia.net]

What is the prognosis for a person with heat cramps? Heat-induced muscle spasms usually resolve without any medical treatment. [emedicinehealth.com]

[…] hr crystalloid infusion consider frusemide infusion 1mg/kg/h consider mannitol 0.25-0.5g/kg early RRT maintain normal potassium, calcium and phosphate levels OUTCOME mortality > 60% permanent neurological deficit – 7-15% factors associated with poor prognosis [lifeinthefastlane.com]

Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. [icd10coded.com]

Epidemiology Acclimatized athletes and laborers at end of work III. Pathophysiology Hyponatremia and volume depletion from profuse sweating Provoked by muscle overload or Fatigue, dehydration or electrolyte disturbance IV. [fpnotebook.com]

"Epidemiology of Exertional Heat Illnesses in Youth, High School, and College Football". Medicine & Science in Sports & Exercise. 48 (8): 1523–9. doi : 10.1249/mss.0000000000000934. [en.wikipedia.org]

He has since completed further training in emergency medicine, clinical toxicology, clinical epidemiology and health professional education. [lifeinthefastlane.com]

Pathophysiology Hyponatremia and volume depletion from profuse sweating Provoked by muscle overload or Fatigue, dehydration or electrolyte disturbance IV. [fpnotebook.com]

While all these theories are being studied, researchers are finding more evidence that the "altered neuromuscular control" hypothesis is the principal pathophysiological mechanism the leads to exercise-associated muscle cramping (EAMC). [sportsmedicine.about.com]

Remember, it is easier to prevent heat illness than to treat it once symptoms develop. Preventing Muscle Cramps Until we learn the exact cause of muscle cramps, it will be difficult to say with any confidence how to prevent them. [sportsmedicine.about.com]

How do you prevent 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. [ksi.uconn.edu]

The Roanoke Alleghany Health District is working to prevent epidemics and the spread of disease, protect the environment, prevent injury, promote and encourage healthy behavior, respond to disasters and assist communities in recovery, and assure the quality [lovelybella.com]

How can we prevent and treat cramps? Eat bananas, right? That used to be the thought, but not so much anymore. While eating bananas may be part of the equation, it certainly isn’t the only thing that should be done to prevent cramps. [fleetfeethartford.com]

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