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Medical Author:

Benjamin Wedro, MD, FACEP, FAAEM

Benjamin Wedro, MD, FACEP, FAAEM

Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.

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Medical Editor:

William C. Shiel Jr., MD, FACP, FACR

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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In this Article

• Heat cramps facts
• What are heat cramps?
• Who is at risk for heat cramps?
• What causes heat cramps?
• What are the signs and symptoms of heat cramps?
• When should an individual seek medical care for heat cramps?
• How are heat cramps diagnosed?
• How are heat cramps treated?
• What are the complications of heat cramps?
• How can heat cramps be prevented
• What is the prognosis for heat cramps?
• Find a local Doctor in your town
• Heat Cramps Index

Heat cramps are the intermittent, involuntary spasm of muscles that occur in an individual who is physically active (for example, working or exercising) in hot or humid weather. They are often associated with dehydration. Heat cramps usually affect the major muscles that are being stressed in the hot environment. Most often these are the thigh and leg (quadriceps, hamstrings, gastrocnemius), the core muscles (abdominal wall and back) and the arm muscles (biceps, triceps).

Heat cramps can also occur after the activity has been completed. For example, construction workers or roofers can develop cramps a few hours after their work shift is over.

While heat cramps tend affect those who are active in a hot environment, it should be noted that heat cramps are one of the symptoms associated with heat exhaustion as part of the spectrum of heat-related illness. Those individuals who have impaired temperature control mechanisms are at higher risk for developing heat-related illness. The body's most effective way of cooling itself is through sweat, and then the sweat evaporates into the environment. Those at most risk for heat cramps include:

• Infants and young children because they depend upon others to avoid the heat, dress them appropriately (avoid swaddling an infant since it prevents air movement over the skin to promote sweat evaporation) and provide enough fluid to drink
  
  
• The elderly because they may have underlying medical conditions, including heart and lung disease, and they can easily become dehydrated
  
  
• People who live by themselves or who cannot afford air conditioning are at higher risk for heat related illness
  
  
• A variety of medications can impair the body's sweat and heat regulation. Examples of drugs include medication prescribed for psychiatric conditions, including antipsychotic medications and tranquilizers. Over-the-counter cold medications and antihistamines also impair the body's temperature control mechanism.
  
  
• Alcohol consumption