How to cool your body down in a heatwave
Your body sheds heat by evaporating sweat. Moving air, light clothing, and a fine mist of water all work with that, and cost nothing.
When a room cannot be made cooler, you can still make yourself cooler. The two are separate problems, and the second one is often easier to solve.
Work with evaporation
Your body’s main cooling mechanism is evaporating sweat off your skin. Every gram that evaporates takes real heat with it. Anything that speeds up evaporation makes you feel cooler, even when the air temperature has not moved at all.
That is why a fan works on a person but not on an empty room, and why a humid 30 °C is so much harder to bear than a dry 30 °C. In saturated air, sweat sits on your skin and does nothing.
The cool yourself checklist
- Use a fan on oscillating mode, not aimed straight at your face. A constant jet on one spot dries eyes and airways and tends to leave you stiff after a few hours
- Wear light, loose clothing in natural fibres. Loose matters more than thin: it lets air circulate against your skin
- Mist water on your skin, particularly on the face, neck, wrists, and forearms. A fine spray plus moving air is the cheapest cooling you have
- Cool your pulse points: a damp cloth on the back of the neck, or running cool water over the inside of your wrists, works quickly
- Cool drinks help, but very cold drinks can upset your stomach when you are overheated
A cool shower, not a cold one
A lukewarm or cool shower lowers your skin temperature and leaves you damp, which keeps evaporation going for a while afterwards. It works well before bed.
An ice-cold shower feels more decisive but is less effective: the cold triggers your blood vessels to constrict, which reduces heat transfer from your core to your skin, and you can end up rebounding warmer.
Slow down
Muscle activity produces heat. During the hottest hours, the useful move is to postpone anything strenuous to early morning or late evening. Cooking, exercise, and moving furniture all add heat to both you and the room. A heatwave is a legitimate reason to do less.
Sleeping through it
- Ventilate the bedroom hard during the cool hours, and shade it aggressively during the day
- A damp towel or light sheet instead of a duvet keeps evaporation working overnight
- A fan across the bed, not pointed at your head, at low speed
- Cool your feet and wrists before lying down. Both are efficient at shedding heat
Know the warning signs
Feeling uncomfortable is normal in a heatwave. These are not:
- Confusion, disorientation, or slurred speech
- A headache that will not shift
- Nausea, vomiting, or dizziness on standing
- Skin that has stopped sweating and turned hot and dry
- A racing pulse that does not settle with rest
Those are signs of heat exhaustion or heatstroke, and heatstroke is a medical emergency. What matters is your safety: always follow your local health agency for further recommendations.