What Causes Heat Cramps?

They often affect muscles used during activity, such as the calves, thighs, shoulders or abdomen. Heat makes the body sweat to cool itself; prolonged sweating can reduce fluid and electrolytes, while muscle fatigue adds strain. Dehydration can therefore accompany or contribute to heat cramps. The spasms may be painful and tight, and the skin may feel hot. Heat cramps can be an early warning that the body is struggling with heat, but they are not the same as heat exhaustion or heatstroke. Symptoms may continue after activity if fluid losses are not replaced.

Stop exercising and move to a cool or shaded place. Rest the affected muscle and gently stretch it; a light massage may help. Sip cool water, and consider an oral rehydration drink if sweating has been heavy and you can drink safely. Loosen excess clothing and avoid returning to strenuous activity until you feel recovered. Preventive steps include regular fluids, breaks in shade and gradual adjustment to hot conditions.

Get urgent medical help if cramps do not settle, keep returning, or occur with confusion, fainting, severe weakness, vomiting, a very high body temperature or hot skin without sweating. These can signal a more serious heat illness. Do not give drinks to someone who is confused or unable to swallow normally; call emergency services instead.

Could dehydration, a medicine or another condition be contributing? Which fluids are suitable during prolonged exercise? How can I safely return to activity in hot weather?