In the UK, heat exhaustion and heatstroke usually only occur during periods of unusually hot weather, such as a heatwave.

The risk may be greater when travelling abroad in hot countries.

At home

Each year, the government operates Heat-Health Watch, a system of four different warning levels based on the expected temperatures. This can be useful when planning activities or preparing for a heatwave.

Public Health England (PHE) has also published a Heatwave plan for England (PDF, 1.15 MB), which provides advice about how to cope during a heatwave and recommendations for preventing heat-related illnesses. The main recommendations are outlined below.

Stay out of the sun 

Stay out of the sun during the hottest parts of the day, particularly 11am-3pm. However, it is important to remember that it can also be very hot before and after these times.

If you have to go out when it is hot, make sure you apply sunscreen, wear a sun hat and stay in the shade where possible.

Keep hydrated

Make sure you drink plenty of cold drinks when it is hot, but avoid drinks containing caffeine and alcohol. Eat cold foods, such as salad and fruit, which have a high water content.

Spraying water on to your skin or placing a damp cloth on the back of your neck will help keep you cool. You could also take a cool bath or shower.

Cool environment

Place a thermometer in your main living room and bedroom to keep a check on the temperature. If possible, move into a cooler room, particularly for sleeping.

Keep windows that are exposed to the sun closed during the day. Open windows at night when the temperature has dropped. Consider replacing metal blinds or dark curtains because they absorb heat.

Have your loft and cavity walls insulated. This will keep the heat in when it is cold and keep it out when it is hot. Use light coloured, reflective external paint.

Turn off non-essential lights and electrical equipment because they generate heat.

Placing bowls of water around your house will also help cool the air through evaporation.

Look out for others

During hot weather, keep an eye on people who are isolated, elderly, ill or very young. Make sure they are able to keep cool. Ensure they are not left alone in stationary cars during a heatwave. This advice also applies to animals.

In hot weather, check on elderly or sick neighbours and elderly family members or friends every day, if possible. Be alert and call a doctor or social services if someone is unwell or if further help is needed.

Travelling abroad

The above advice also applies if you are travelling abroad to a hot country.

It is important to remember that it takes the body 7-10 days to acclimatise to a hotter environment. Until that time, you will sweat less than you should. Drink water regularly, avoid staying in the heat too long and wear loose, light clothing. 

Athletes should acclimatise for three to four days before undertaking anything but light physical activity. Build up activity levels gradually over a two to three week period.

Alcohol is also an important factor to consider when travelling abroad. Drinking too much alcohol can affect your ability to judge temperature and move to somewhere cooler. It can also lead to dehydration, increasing the risk of heat exhaustion and heatstroke.