Britain's Chief Medical Officer has outlined measures to keep people safe in unusually hot weather.
In severe heat the human body can overheat and dehydrate, leading to heat exhaustion or heatstroke. Heatstroke can result in irreversible damage to the body, including the brain, or death.
The plan from Sir Liam Donaldson identifies four levels of alert and action for the NHS and other public bodies. High temperatures would trigger the 'Heat-Health watch' system that will operate from 1 June to 15 September.
Actions range from giving advice on how to keep cool at level one, through to level four where heat can pose a serious threat to health, and the emergency services may be involved.
The contingency plan follows widespread problems across Northwest Europe last summer and predicted climate change. There were 2,000 'excess deaths' in England during the August heatwave last year.
Temperatures across much of the UK over the next few days are forecast to reach 28 to 30 Degrees Centigrade. Officials are preparing for early use of the new service.
A leaflet called 'Heatwave - a guide to looking after yourself' will be distributed nationally. It includes the following advice:
- If a heatwave is forecast, try and plan your day in a way that allows you to stay out of the heat
- If you can, avoid going out in the hottest part of the day (11am - 3pm)
- If you must go out, stay in the shade. Wear a hat and light loose fitting clothes, preferably cotton. If you will be outside for some time, take plenty of water with you.
- Take cool showers or baths and splash yourself several times a day with cold water, particularly your face and the back of your neck
- Eat as you normally would. Try to eat more cold food, particularly salads and fruit, which contain water.
Chief Medical Officer, Sir Liam Donaldson said although uncommon, heatwaves cause problems for the elderly, babies and young children. Precautions should be taken, he said.
"In contrast to deaths associated with cold snaps in winter the risk in mortality follows very sharply, within one or two days of the temperature rising.
"This means that by the time a heatwave starts the window of opportunity for effective action is very short indeed. It is therefore crucial that we are properly prepared for this situation."