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].

• Collapse

  […] progress End-organ damage: brain damage, kidney failure, liver failure, blood clotting abnormalities related to duration of elevated temperature Treatment of Heat Stroke ABC Unconscious patient may vomit and aspirate IV: no more than 2L unless circulatory collapse [armystudyguide.com]

  The exact temperature at which cardiovascular collapse occurs varies among individuals because coexisting disease, drugs, and other factors may contribute to or delay organ dysfunction. [emedicine.medscape.com]

  Children and the elderly show the fastest progression of symptoms and can collapse suddenly. Those on certain medications can suffer from heat illness, as well, as medications can alter the way the body handles heat and sun. [skinsight.com]

• 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]

• High Fever

  Heat stroke Warm, dry skin High fever, usually over 104° F (or 40° C) Rapid heart rate Loss of appetite Nausea Vomiting Headache Fatigue Confusion Agitation Lethargy Stupor Seizures, coma, and death are possible Move to a cool place and rest. [urmc.rochester.edu]

  Heat stroke Warm, dry skin high fever, usually over 104° F (or 40° C) Rapid heart rate Loss of appetite Nausea Vomiting Headache Fatigue Confusion Agitation Lethargy Stupor Seizures, coma, and death are possible Move to a cool place and rest. [hopkinsmedicine.org]

• Anorexia

  The vulnerable groups include: infants and babies under two years elderly persons, especially elderly women those with long standing diseases like kidney and heart disease, diabetes mellitus, anorexia, Parkinson’s disease, Alzheimer’s disease, cystic [news-medical.net]

  Signs and symptoms of heat exhaustion ( Table 3 ) 7, 8, 12, 13 include fatigue and malaise, anorexia, nausea, vomiting, anxiety, and confusion. [aafp.org]

• Diarrhea

  Crohn's disease and ulcerative colitis are two types of inflammatory bowel disease, and have symptoms including stomach pain, diarrhea, and bleeding. [livescience.com]

  When to seek medical advice Call your healthcare provider right away if any of these occur: Inability to keep fluids down Vomiting or diarrhea Hot flushed skin Worsening symptoms or new symptoms Call 911 Call 911 for any of these symptoms of severe heat [fairview.org]

  Heat exhaustion Muscle cramps Pale, moist skin Usually has a fever over 100.4° F (or 34° C) Nausea Vomiting Diarrhea Headache Fatigue Weakness Anxiety, and faint feeling Move to a cool place and rest. [urmc.rochester.edu]

• Loss of Appetite

  Primary symptom: body temperature higher than 105 degrees Fahrenheit or 40.6 degrees Celsius.Other symptoms include: warm and dry skin, fever, increased heart rate, shallow breathing, loss of appetite, nausea, vomiting, throbbing headache, dizziness, [theydiffer.com]

  Loss of appetite. IDENTIFY SIGNS AND SYMPTOMS OF HEAT EXHAUSTION Other Signs and Symptoms of Heat Exhaustion Heat cramps. Nausea (with or without vomiting). Chills (“gooseflesh”). Rapid breathing. Urge to defecate. Tingling in hands or feet. [armystudyguide.com]

  Heat stroke Warm, dry skin High fever, usually over 104° F (or 40° C) Rapid heart rate Loss of appetite Nausea Vomiting Headache Fatigue Confusion Agitation Lethargy Stupor Seizures, coma, and death are possible Move to a cool place and rest. [urmc.rochester.edu]

  Heat stroke Warm, dry skin high fever, usually over 104° F (or 40° C) Rapid heart rate Loss of appetite Nausea Vomiting Headache Fatigue Confusion Agitation Lethargy Stupor Seizures, coma, and death are possible Move to a cool place and rest. [hopkinsmedicine.org]

• Sweating

  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. This leads to hyponatremia. [symptoma.com]

  During sweating, salts (electrolytes) and fluids are lost, but drinking large quantities of water dilutes the salts, causing cramps. Heavy sweating is most likely to occur on warm days, especially during or after strenuous exertion. [msdmanuals.com]

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

  Can deacclimatize as quickly Results: sweat at lower temperature increased volume of sweat decrease in amount to salt secreted in sweat increased heat dissipation = lower core body temperature End result: Decreased risk for heat injury! [armystudyguide.com]

• Dry Skin

  Primary symptom: body temperature higher than 105 degrees Fahrenheit or 40.6 degrees Celsius.Other symptoms include: warm and dry skin, fever, increased heart rate, shallow breathing, loss of appetite, nausea, vomiting, throbbing headache, dizziness, [theydiffer.com]

  A person who is experiencing heatstroke might have very dry skin from dehydration. Heat emergencies usually occur when someone has exercised too much in hot weather. [healthline.com]

  Symptoms include: confusion due to lack of blood flow to the brain reddened dry skin lack of sweat organ failure convulsions or seizure. [nbcnews.com]

  Symptoms of Heat Stroke [ edit ] Unconscious or has a markedly abnormal mental status Flushed, hot, and dry skin (although it may be moist initially from previous sweating or from attempts to cool the person with water) May experience dizziness, confusion [en.wikibooks.org]

  Early signs of heat illness Heavy sweating Muscle cramps Paleness Dizziness Nausea Fainting Serious signs of heat illness Fed, hot and dry skin Fapid pulse Continued headache, dizziness and nausea Acting confused Unconscious Athletes should keep an eye [eu.ydr.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]

• Muscle Spasm

  Muscle spasms are the only sign of heat cramps. [emedicinehealth.com]

  As dehydration sets in, subtle twitches or cramping can progressively turn into painful muscle spasms. For James, it was too late to replenish his stores of fluids and electrolytes in the remaining minutes of the game. [menshealth.com]

  See also heat exhaustion. heat cramp Skeletal muscle spasm caused by the excess fluid and/or electrolyte loss that occurs with profuse sweating. The usual muscles affected are those used during work, i.e., the hand, arm, or leg muscles. [medical-dictionary.thefreedictionary.com]

  Severe muscle spasms occur as a result of salt and water loss following exertion, most often in the hands, calves, and feet. Muscle spasms can spontaneously stop on their own, but lingering symptoms of soreness often persist for 24-48 hours. 2. [nbcnews.com]

• 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]

• Carpopedal Spasm

  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]

• 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]

• Excitement

  Scottie cramp, Scotch cramp an inherited defect in Scottish terriers that occurs as hyperkinetic episodes from an early age, but may only be precipitated by exercise or excitement. [medical-dictionary.thefreedictionary.com]

  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. [symptoma.com]

  As a result of a consequent contracted interstitial compartment, axon terminals of selected motor neurons can become hyper-excitable and spontaneously discharge. [ncbi.nlm.nih.gov]

  Better known as an antimalarial drug (and the ingredient that gives tonic water its bitter taste), quinine seems to help leg cramps by decreasing the excitability of nerves. [health.harvard.edu]

• Agitation

  Other symptoms for heat stroke include warm and dry skin, fever, increased heart rate, shallow breathing, loss of appetite, nausea, vomiting, throbbing headache, dizziness, light-headedness, fatigue, confusion, muscle weakness or cramps, agitation, lethargy [theydiffer.com]

  Symptoms include: headache low-grade fever nausea or vomiting increased thirst generalized weakness muscle ache or cramping Feeling agitated and anxious are common and some people may even faint as blood pressure tries to compensate, but ultimately lowers [nbcnews.com]

  Heat stroke Warm, dry skin High fever, usually over 104° F (or 40° C) Rapid heart rate Loss of appetite Nausea Vomiting Headache Fatigue Confusion Agitation Lethargy Stupor Seizures, coma, and death are possible Move to a cool place and rest. [urmc.rochester.edu]

  Heat stroke Warm, dry skin high fever, usually over 104° F (or 40° C) Rapid heart rate Loss of appetite Nausea Vomiting Headache Fatigue Confusion Agitation Lethargy Stupor Seizures, coma, and death are possible Move to a cool place and rest. [hopkinsmedicine.org]

• Stupor

  Celsius.Other symptoms include: warm and dry skin, fever, increased heart rate, shallow breathing, loss of appetite, nausea, vomiting, throbbing headache, dizziness, light-headedness, fatigue, confusion, muscle weakness or cramps, agitation, lethargy, stupor [theydiffer.com]

  Heat stroke Warm, dry skin High fever, usually over 104° F (or 40° C) Rapid heart rate Loss of appetite Nausea Vomiting Headache Fatigue Confusion Agitation Lethargy Stupor Seizures, coma, and death are possible Move to a cool place and rest. [urmc.rochester.edu]

  Heat stroke Warm, dry skin high fever, usually over 104° F (or 40° C) Rapid heart rate Loss of appetite Nausea Vomiting Headache Fatigue Confusion Agitation Lethargy Stupor Seizures, coma, and death are possible Move to a cool place and rest. [hopkinsmedicine.org]

• Lethargy

  […] degrees Celsius.Other symptoms include: warm and dry skin, fever, increased heart rate, shallow breathing, loss of appetite, nausea, vomiting, throbbing headache, dizziness, light-headedness, fatigue, confusion, muscle weakness or cramps, agitation, lethargy [theydiffer.com]

  Heat stroke Warm, dry skin High fever, usually over 104° F (or 40° C) Rapid heart rate Loss of appetite Nausea Vomiting Headache Fatigue Confusion Agitation Lethargy Stupor Seizures, coma, and death are possible Move to a cool place and rest. [urmc.rochester.edu]

  Heat stroke Warm, dry skin high fever, usually over 104° F (or 40° C) Rapid heart rate Loss of appetite Nausea Vomiting Headache Fatigue Confusion Agitation Lethargy Stupor Seizures, coma, and death are possible Move to a cool place and rest. [hopkinsmedicine.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

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

  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]

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]

Injury Heat Cramps Heat Exhaustion Heat Stroke Heat Cramps Painful cramping of the larger muscle groups legs, arms, abdomen Due to excessive loss of salt through heavy sweating plus several hours of sustained exertion acclimatization decreases risk Treatment [armystudyguide.com]

The treatment priority with heat stroke is to call EMS and cool the victim down. When you provide first aid for heatstroke, remember that this is a true life-and-death emergency. [en.wikibooks.org]

[…] 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]

Prevention See Heat Illness Prevention Prior to work or Exercise : Adequate Stretching Adequate water intake With Exercise (especially longer than 1 hour) Ingest a drink containing Glucose and Sodium Images: Related links to external sites (from Bing) [fpnotebook.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 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]

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 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]

1. Bergeron MF. Heat cramps during tennis: a case report. Int J Sport Nutr. 1996;6(1):62-68.
2. Stofan JR, Zachwieja JJ, Horswill CA, Murray R, Anderson SA, Eichner ER. Sweat and sodium losses in NCAA football players: a precursor to heat cramps? Int J Sport Nutr Exerc Metab. 2005;15(6):641-652.
3. Jung AP, Bishop PA, Al-Nawwas A, Dale RB. Influence of hydration and electrolyte supplementation on incidence and time to onset of exercise-associated muscle cramps. J Athl Train. 2005;40(2):71-75.
4. Bentley S. Exercise-induced muscle cramp: proposed mechanisms and management. Sports Med. 1996;21(6):409-420.
5. Schwellnus MP, Derman EW, Noakes TD. Aetiology of skeletal muscle ‘cramps’during exercise: a novel hypothesis. J Sports Sci. 1997;15(3):277-285.
6. Bergeron MF. Heat cramps: fluid and electrolyte challenges during tennis in the heat. J Sci Med Sport. 2003;6(1):19-27.
7. Donoghue A, Sinclair MJ, Bates GP. Heat exhaustion in a deep underground metalliferous mine. Occup Environ Med. 2000;57(3):165-174.
8. Layzer RB. The origin of muscle fasciculations and cramps. Muscle Nerve. 1994;17(11):1243-1249.