The Meteorological Office has declared a level two heatwave alert – meaning there is a significant chance that temperatures over the next few days could pose significant health risks.

Dr Andrew Furber, director of public health at NHS Wakefield District, said: "Most of us enjoy the sunny weather but extreme heat, when temperatures stay really high day after day, can seriously damage your health.

"If you don't drink enough fluid you can get dehydrated causing your body to overheat.

"Heat exhaustion can happen to anyone in hot weather. The symptoms include headaches, dizziness, nausea and vomiting, muscle weakness or cramps, pale skin, and a high temperature.

"If this happens you should find somewhere cool to rest, drink plenty of water or fruit juice.

"If you can, take a lukewarm shower, or sponge yourself down with cold water. If heat exhaustion isn't treated it can lead to heatstroke, which can be dangerous and even fatal."

High temperatures can be dangerous, especially to the elderly, the very young and people with chronic or long-term medical condition.

To avoid ill health caused by the heat, the primary care trust is advising residents to:

Enjoy the weather but try to stay cool. Avoid going outside between 11am and 3pm as this is the hottest part of the day. Spend time in the shade and avoid strenuous activity.

Help others. Check up on neighbours, relatives and friends who may be less able to look after themselves.

Drink water or fruit juice regularly. Avoid tea, coffee and alcohol. If you do drink alcohol make sure you have lots of water or other non-alcoholic drinks as well.

Keep rooms cool by using shade or reflective material external to the glass, or if not possible by closing pale 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. If safe, open windows at night when the air is cooler.

People with heart problems, breathing difficulties or serious illnesses may find their symptoms become worse in hot weather. Make sure you have enough medicines in stock and take extra care to keep cool.

Dr Furber added: "If you or any one else feels unwell, drink water and go somewhere cool to rest.

"If symptoms such as breathlessness, chest pain, confusion, dizziness, weakness or cramps get worse or don't go away, seek medical help by calling NHS Direct on 0845 4647 or contacting your doctor for advice."

For the weather forecast and any high temperature health warnings visit www.metoffice.gov.uk.

Online advice about heat exhaustion and heatstroke is available at www.nhsdirect.nhs.uk and information about Cancer Research UK's SunSmart campaign can be found at http://info.cancerresearchuk.org/healthyliving/sunsmart.