Muscle Cramps—Heat Illness

Also called: Heat exhaustion, Sunstroke

Your body normally cools itself by sweating. During hot weather, especially with high humidity, sweating just isn’t enough. Your body temperature can rise to dangerous levels and you can develop a heat illness. Most heat illnesses occur from staying out in the heat too long. Exercising too much for your age and physical condition are also factors. Older adults, young children and those who are sick or overweight are most at risk. Drinking fluids to prevent dehydration, replenishing salt and minerals, and limiting time in the heat can help.

Heat-related illnesses include

• Heatstroke – a life-threatening illness in which body temperature may rise above 106° F in minutes; symptoms include dry skin, rapid, strong pulse and dizziness
• Heat exhaustion – an illness that can precede heatstroke; symptoms include heavy sweating, rapid breathing and a fast, weak pulse
• Heat cramps – muscle pains or spasms that happen during heavy exercise
• Heat rash – skin irritation from excessive sweating

Centers for Disease Control and Prevention

• Heat emergencies (Medical Encyclopedia)
• How to avoid overheating during exercise (Medical Encyclopedia)
• Protecting Workers from Heat Stress (Occupational Safety and Health Administration)
• Protecting Yourself from Heat Stress (National Institute for Occupational Safety and Health) – PDF

Also called: Charley horse

Muscle cramps are sudden, involuntary contractions or spasms in one or more of your muscles. They often occur after exercise or at night, lasting a few seconds to several minutes. It is a very common muscle problem.

Muscle cramps can be caused by nerves that malfunction. Sometimes this malfunction is due to a health problem, such as a spinal cord injury or a pinched nerve in the neck or back. Other causes are

• Straining or overusing a muscle
• Dehydration
• A lack of minerals in your diet or the depletion of minerals in your body
• Not enough blood getting to your muscles

Cramps can be very painful. Stretching or gently massaging the muscle can relieve this pain.

• Charley horse (Medical Encyclopedia)
• Muscle cramps (Medical Encyclopedia)