General information

Heatstroke is caused by excess body temperature and dehydration. Heatstroke can develop without physical exertion. Older people, small children and anyone already dehydrated (due to e.g. diarrhoea) are particularly at risk. The symptoms may include:

  • Headache
  • Nausea
  • Dizziness
  • Irritability
  • Confusion

A person suffering from heatstroke may behave in an unusual manner or they may be slower than usual and appear lost or confused. Sometimes the symptoms include muscle cramps.


Take the person suffering from heatstroke to the shade and take off extra clothes. It is important to cool down and rehydrate the body. You can help by sprinkling or pouring water directly onto the skin.

Apply cold cloths to the head and the neck, and place cold packs in the armpits or hips. Don’t place cold packs or ice directly on to skin to avoid cold injuries.

The person suffering from heatstroke should rest and raising the head may help them feel better. Air flow is also an effective way of cooling down, so ensure proper ventilation and use fans if necessary. Give the patient cool water to drink.

If the feet are swollen because of the heat, make sure the patient gets rest with legs elevated, and give them plenty of fluids to drink. If diuretics have been prescribed, follow the doctor’s instructions.

If the patient has muscle cramps, you may give them energy drinks or saline water (half a teaspoon of salt per two litres of water).

The important thing is to prevent heatstroke in the first place. Drink plenty of liquids if you spend time in the sun. If your urine is dark yellow and low in volume, and you feel thirsty, you are dehydrated. Drinking alcohol, coffee or tea only makes the situation worse. Cover your head and neck and wear lightweight loose air-circulating fabrics. Avoid physical exertion, but if you have to work in the sun, make sure you take frequent breaks.

When should you seek medical advice?

In the case of severe symptoms (cramps, confusion, fainting, severe fatigue, visual disturbances, and lack of sweating and urinating) you should seek immediate medical advice and in the case of emergency always call 112.

This Self-care instruction has been produced in collaboration with Duodecim Terveyskirjasto

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Updated  5.6.2020