Extreme heat

Planning ahead

Sunlight is essential for our health and wellbeing.

In the UK, from late March to the end of September, we get most of our vitamin D from sunlight. Vitamin D is essential for healthy bones. However, excessive exposure to high temperatures during summer can be detrimental to our health.

Every year there are excess deaths as a result of heatwaves. Effective action, taken early, can reduce the impacts of exposure to excessive heat.

Most of these actions are simple. To be effective, preventive measures need to be planned in advance.

Tips for coping in hot weather

  • shut windows and pull down shades or curtains when it is hot outside
  • open windows for ventilation when it is cooler, check out the Beat the Heat: Keep Cool at Home checklist
  • turn off non-essential lights and electrical items as these generate heat
  • identify the coolest room in the house so you know where to go to keep cool
  • plan ahead to make sure you have enough supplies, such as food, water and any medications you need
  • if you have a health condition, keep medicines below 25°C or in the refrigerator
  • stay out of the sun and don't go out between 11am and 3pm, the hottest part of the day
  • look out for others around you, especially older people, young children and babies and those with serious long-term illnesses including heart, lung or kidney illness, diabetes or Parkinson's disease, also take extra care if you are pregnant
  • keep strenuous physical exercise to a minimum between 11am and 3pm, if you are working or exercising outdoors
  • have cool baths or showers, and splash yourself with cool water
  • drink cold drinks regularly, such as water and diluted fruit juice, avoid alcohol, caffeine (tea, coffee and cola) and drinks high in sugar
  • listen to alerts on the radio, TV and social media and visit the MetOffice website for the latest forecasts
  • wear loose, cool clothing, a hat and UV sunglasses, preferably wraparound, to reduce UV exposure to the eyes, walk in the shade if you go outdoors
  • use sunscreen that has a sun protection factor (SPF) of at least 15 to protect against UVB and at least 4 star UVA protection - visit the NHS Choices website for more information about sunscreen and sun safety
  • never leave anyone in a closed parked vehicle, especially babies, young children or animals

If you're worried about someone you know, visit Summer Health information on the NHS Choices website

For advice on reducing the risks, call the non-emergency 111 number or visit your local chemist.

Children's safety

During hot weather, it is important to be aware of water and window safety for babies and children. For more information about water safety for children and accidents to children visit the Royal Society for the Prevention of Accidents.

Air quality

Smogs can accompany heatwaves. It can lead to high concentrations of nitrogen dioxide and particulate matter.

Increased ozone levels can be caused by some pollutants reacting with sunlight.

Adults and children with heart or lung problems are at greater risk of symptoms. Follow your doctor's usual advice about exercising and managing your condition. Very sensitive individuals may experience health effects even on low air pollution days.

Information on the latest pollution levels, air quality forecasts, recommended actions and health advice is available from the Defra UK-Air website or by calling 0800 55 66 77.


During hot weather, dehydration is a common and serious risk. It's important to balance food and fluid intake between fasts. Drink plenty of water.

During Ramadan, if you or someone you know, starts to feel unwell, disoriented or confused, or collapses or faints, stop fasting and have a drink of water or other fluid.

This is especially important for older adults, those with:

  • with controlled medical conditions such as low or high blood pressure, diabetes
  • are receiving dialysis treatment

The Muslim Council of Britain has confirmed that breaking fast in such conditions is allowable under Islamic law. Also, make sure to check on others in the community who may be at greater risk. Keep an eye on children to ensure they are having a safe and healthy Ramadan.

Priority services

Heatwaves may affect services, such as power and water supplies, and transport.

Some vulnerable people can be registered as "priority users" of some utilities. This means that the companies will take care of these people. They will prioritise recovery efforts to help them if their services are interrupted for any reason.

You can register with:

Thames Water also provides guidance on what to do if you have no water or low water pressure.

More information

Each year the government releases information on how to keep you safe during a heatwave:

The heatwave plan runs from 1 June to 15 September each year.

Crime prevention

Warm weather offers some opportunities to thieves and for other types of crime.

Thames Valley Police suggest a few simple measures to reduce the chances of you being a victim of crime.