11 Aug 2022


– The information has been reviewed by Dr. Ko Hiu Fai

If the cooling system (sweating) for regulating body temperature fails under extreme heat, our body temperature can rise rapidly to 41oC within 10 to 15 minutes, known as heatstroke. Mild symptoms include headache, dizziness, nausea, weakness, thirst, and profuse sweating. Without immediate rest and treatment, the patient may suffer heat cramps or febrile convulsion. If rhabdomyolysis occurs, symptoms may include irregular heartbeat, seizure, or liver damage. Heatstroke may cause permanent disabilities or death, with a death rate at around 40-50%, and as high as 70% for people aged above 50. Therefore, it should not be taken lightly.


First Aid

  • Call 999 for an ambulance, or seek medical assistance at your nearest Urgent Care Clinic.
  • Move the patient in the shade, remove excess clothing that may obstruct breathing.
  • Help the patient to cool down quickly, wet/ sponge their skin with cool water, fanning, or placing wet cloth / ice packs around the patient’s head, neck, armpits and groin.
  • Let the patient drink more water or drinks with electrolytes if he/ she is conscious.



Beware of the Very Hot Weather Warning issued by the Hong Kong Observatory, and wear loose and light-coloured clothing to reduce heat absorption. Drink plenty of water, but avoid consuming caffeinated drinks like tea or coffee and alcohol, as these may increase urine excretion and lead to dehydration.