What should you know about heat cramp prevention?

Heat cramps are painful, involuntary muscle contractions during or after exertion in hot conditions. Heavy sweating removes fluid and salts, while tired muscles are repeatedly shortened and loaded. The calves, thighs, arms, and abdomen may be affected. Dehydration can increase the strain, especially when activity is prolonged or someone is not acclimatised to the heat.

A cramp is a warning to stop and recover, not a challenge to push through. Muscle aches or cramps that continue after cooling and drinking need a different assessment, particularly if weakness or dark urine develops.

Start exercise gently and build intensity over several days in hot weather. Choose cooler times when possible, wear loose breathable clothing, and take regular shaded breaks. Drink regularly rather than waiting until intense thirst, and replace fluids after heavy sweating. A clinician or pharmacist can advise whether an oral rehydration therapy product is suitable for your situation.

At the first sign of a cramp, stop the activity, move somewhere cool, and gently stretch the affected muscle. Avoid forceful stretching or returning to strenuous exercise while pain remains. People with heart, kidney, or fluid-balance conditions should ask for individual hydration advice.

Seek urgent help for confusion, fainting, severe weakness, seizures, breathing difficulty, or inability to drink. Prompt assessment is needed if cramps are accompanied by very little urine, dark urine, persistent vomiting, or worsening dehydration.

Arrange a medical review if cramps repeatedly occur despite rest and hydration, happen in mild conditions, or begin after a new medicine. Recurrent cramps may need assessment of medicines, nutrition, nerve function, or other causes.

How much activity and fluid replacement is appropriate for me? Could my medicines or health conditions affect heat tolerance? What should I use if ordinary fluids do not replace what I lose through sweating?