Muscle Cramps Due to Heat: What to Know

Hot weather and hard activity increase sweating. Losing fluid and salts, while repeatedly using a muscle, can make it tighten and stay contracted. Cramps often affect the calves, thighs, arms or abdomen, but any working muscle can be involved. Heat cramps are different from a simple muscle strain, which often follows an isolated injury. Recurrent cramps can also have other contributors, including dehydration or a medicine effect.

Stop the activity and move to a cool, shaded place. Rest the affected muscle, then gently stretch it without bouncing; light massage may also relax the spasm. Sip water, and consider an oral rehydration drink if you have been sweating heavily. Loosen extra clothing and cool the skin with a wet cloth. Do not return to strenuous activity while the pain or weakness continues. People with kidney disease or fluid restrictions should ask a clinician which drink is suitable.

Get urgent help if cramps occur with confusion, fainting, severe weakness, vomiting, trouble breathing, a very hot body or inability to drink. These can signal a more serious heat illness. Arrange medical advice if the cramp does not settle after cooling and rest, keeps returning, or began without heat or exertion. A clinician may review hydration, medicines, circulation and conditions such as peripheral arterial disease.

Ask: Could a medicine or health condition be contributing? How much fluid is appropriate for me? Should I have an electrolyte assessment? What activity and cooling plan fits my health?