1. 7 Most Effective Exercises Pictures
2. Take the Exercise and Fitness Quiz!
3. How to Build a Better Butt Slideshow

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.

View Full Profile

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.

View Full Profile

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

While it was thought that dehydration and electrolyte imbalance was the cause of muscle cramping, there are alternative theories as to why muscles cramp when the body is exposed to heat.

Since heat cramps begin after significant exercise in a hot environment where the affected individual begins sweating profusely, the theory was that muscles were depleted of water and sodium affecting their ability to contract and relax. Some new research suggests that as the muscles tire from excess activity and work, the ability for the muscle to regulate its own contraction is lost and this is called altered neuromuscular control. Regardless of the cause, the diagnosis and treatment for heat cramps remain the same.

Heat cramps are the earliest symptoms of the spectrum of heat-related illness. There is usually significant sweating with involuntary spasm of the large muscles in the body. The muscles that cramp are usually those that have been stressed. Runners and football players tend to get leg muscle cramps, but people who lift can get cramps in the muscles of the arms or the core trunk muscles like the abdominal muscles (rectus abdominus). Heat cramps usually begin after significant activity has occurred but they can occur after the activity has been completed.

Individuals with heat cramps tend only to have muscle cramps. If an individual has other signs or symptoms such as lightheadedness, weakness, nausea and vomiting, and headache he or she may be suffering from heat exhaustion. Affected individuals who have stopped sweating or who develop a fever and become confused may have heat stroke which is a true medical emergency.