Ways to prevent heat exhaustion

Heat exhaustion develops when heat and sweating cause the body to lose fluid and salt faster than they are replaced. Risk rises during exercise, outdoor work, crowded settings and humid weather. Older adults, young children, pregnant people and those with chronic illness may need extra planning. Early symptoms can include excessive sweating, headache, dizziness, unusual tiredness, thirst or dark urine.

Check the weather and move strenuous tasks to a cooler part of the day. Wear loose, light-coloured clothing, a hat and breathable footwear. Use shade, air conditioning or a cool room for regular breaks. Drink at intervals rather than waiting until thirst is strong, and replace fluids after heavy sweating; ask a clinician about electrolyte drinks if you have a medical condition. Never leave a child, older person or pet in a parked vehicle. Increase outdoor activity gradually when the weather changes, and work with a partner who can notice early symptoms.

Stop activity and move to a cool place if sweating, headache, dizziness or thirst develops. Loosen clothing, cool the skin and sip fluids if you are alert and able to swallow. Get urgent help for confusion, fainting, a seizure, severe weakness, inability to drink or symptoms that do not improve promptly. Heat illness can worsen quickly, particularly when dehydration is also present.

Do my medicines or health conditions increase heat risk? How should I replace fluids after heavy sweating? What warning signs mean I should stop exercising or seek urgent care?