How long heat exhaustion lasts

Mild symptoms such as tiredness, thirst, headache or light-headedness may ease after leaving the heat and replacing lost fluids. Recovery can take longer when exposure was prolonged, sweating was heavy, fluid intake was limited, or another illness is present. Improvement should be gradual rather than followed by a return of symptoms. [Heat Exhaustion](/conditions/heat-exhaustion/) can overlap with [Dehydration](/conditions/dehydration/), so the two may need separate assessment.

Stop exertion and rest in a cool, ventilated place. Sip water or an oral rehydration drink if you are awake and can swallow; avoid gulping large amounts if nauseated. Use damp clothing, a fan or a cool shower, and wear light clothes. Do not return to intense exercise or direct sun while symptoms remain. Keep notes on dizziness, thirst, sweating and urine colour so you can describe the pattern accurately.

Seek emergency help for confusion, fainting, seizure, severe breathing trouble, inability to drink or a change in alertness. Obtain urgent medical advice if symptoms are not clearly improving, return after initial relief, or include repeated vomiting, very dark urine, little urination or severe headache. These features can indicate a more serious heat-related illness.

Ask when it is safe to work or exercise in heat again, how much fluid is suitable for you, and whether your medicines or medical history increase risk. Ask which symptoms should prompt immediate reassessment if they recur.