What should you know the day after heat exhaustion?

Heat exhaustion develops when heat exposure and fluid or salt loss overwhelm the body's ability to cool itself. The next day you may still feel tired, thirsty, dizzy or headachy, especially after sweating heavily. Dark urine can suggest that you need more fluid, although urine colour is not a complete health check. Ongoing symptoms may also reflect dehydration or another illness. Heat exhaustion can progress to heatstroke, which is an emergency, so improvement matters more than simply waiting for a particular recovery time.

Stay in a cool environment, rest and avoid strenuous exercise, direct sun and alcohol while you recover. Sip water and, if a clinician recommends it, use an oral rehydration drink; drinking very large amounts quickly can be harmful. Eat normally if you can tolerate food. Wear loose, light clothing and ask someone to check on you if you remain weak or dizzy. Do not return to intense heat or sport until symptoms have settled and a clinician has advised that it is sensible, particularly if you fainted or have a chronic condition.

Seek urgent help for confusion, collapse, seizure, loss of consciousness, very hot skin, inability to drink, repeated vomiting or symptoms that do not improve with cooling and fluids. A severe headache, worsening dizziness, persistent dark urine or marked weakness also deserves prompt medical assessment. Do not leave someone with suspected heatstroke alone or ask them to travel unaided.

Ask when you can safely resume work, exercise or outdoor activity, whether medicines increase heat risk, and how to replace fluids safely. Discuss a prevention plan if you have repeated excessive sweating, heat intolerance or symptoms after modest heat exposure.