How to stay cool in a heatwave

While the UK doesn’t see heatwaves like those found in some other countries, we do occasionally have periods when the heat and humidity are much higher than we’re used to having. Many of us are not prepared when that happens. Heatwaves can be dangerous, especially for the very young, the elderly or those with chronic or long-term medical conditions.

Each year, health departments put together heatwave emergency plans ready to put into action if a heatwave is forecast.

Sensible precautions

The Met Office, the NHS and Age UK all list sensible measures you can take to keep cool. They are:

• Plan ahead: stock up with supplies so that you don't need to go out during extreme heat and think about what medicines, food and non- alcoholic drinks you'll need.
• Keep out of the heat. Stay indoors during the hottest time of the day: 11am to 3pm.
• If you do go out, wear a hat and stay in the shade as much as you can.
• Avoid strenuous activity and limit jobs like housework and gardening to the early morning or evening when it’s cooler.
• Identify the coolest room in the house so you can go there to keep cool.
• Keep rooms cool by using shade or reflective material external to the glass, or if that is not possible, by closing light-coloured curtains (metallic blinds and dark curtains can make the room hotter).
• Keep the windows closed while the room is cooler than it is outside and, if it's safe, open windows at night when the air is cooler. Night cooling is important as it allows the body to recuperate.
• If you’re planning to travel, check the forecast at your destination too.
• Drink plenty of fluids, even if you don’t think you’re thirsty. Avoid alcohol, which can dehydrate the body.
• Try to eat as you normally would. Not eating properly may exacerbate health-related problems.
• Try to stay cool by taking tepid showers or baths and/or sprinkle yourself several times a day with cool water.
• If driving, keep your vehicle well ventilated to avoid drowsiness. Take plenty of water with you and have regular rest breaks.
• If travelling by public transport always take a bottle of water with you.
• Avoid too much exercise, which can cause heat exhaustion or heat stroke, and can even be fatal. Watch for signs of heat stress, an early sign is fatigue.
• Help others: check up on neighbours, relatives and friends who may be less able to look after themselves (for example, if they have mobility or heart problems).

Heat exhaustion and heatstroke

Heat exhaustion can happen to anyone in hot weather. If it isn't treated it can lead to heatstroke, which can be dangerous and even fatal.

Heat exhaustion is when the temperature inside the body, known as the core temperature, rises above the normal 37°C (98.6°F) towards 40°C (104°F).

At that temperature, heavy sweating causes the levels of water and salt in the body begin to drop. This causes symptoms such as nausea, feeling faint and heavy sweating.

The NHS says if a person with heat exhaustion is taken quickly to a cool place and given plenty of water to drink, they should begin to feel better within half an hour and experience no long-term complications. Without treatment, they could develop heatstroke.

Heatstroke occurs when the body is unable to regulate its temperature. The body's temperature rises rapidly above 40°C (104°F), the sweating mechanism fails and the body is unable to cool down.

Heatstroke is very serious and should be treated immediately – dial 999 for an ambulance if you suspect heatstroke. Treatment involves quickly cooling down the body to lower the core temperature.

If treated swiftly, 90% of people with heatstroke survive. If not, the survival rate is as low as 20% among vulnerable people such as the elderly.