LONDON - TEMPERATURES are set to soar across many parts of Britain this week with the mercury possibly hitting 33 degrees Centigrade in London on Thursday, prompting the Met Office to issue its first heatwave warning of the year.

It will be the first significant heatwave in Britain since 2006, with temperatures much the same as Mediterranean resorts.

Levels of 29 or 30 degrees are expected in London on Monday, rising a notch each day until Thursday to 32 or 33.

'We are certainly looking at the low 30s so it's pretty hot weather,' said Met Office forecaster John Hammond. 'They are the sort of temperatures comparable to many Mediterranean resorts - though not as hot as cities in the interior like Seville.'

The hottest day of the year so far was last Thursday, with Heathrow Airport reaching 28 degrees. The hottest ever in Britain was 38.9 recorded at Faversham, Kent, on Aug 10, 2003.

Outside London, the Met Office said temperatures would rise from about 22 degrees into the high 20s in southern England and the Midlands, with Scotland also getting up to 25 degrees.

Night time temperatures would also stay high, with thermometers not dropping below 16 degrees in the countryside and 18 in the cities.

The Department of Health has advised people to keep their homes as cool as possible and remember the needs of friends, relatives and neighbours who could be at risk.

It said the elderly and the ill are particularly vulnerable during hot weather, with the most oppressive conditions occurring in urban areas.

Heat can make heart and respiratory problems worse, and in extreme cases can lead to potentially fatal heat stroke, it warned. -- REUTERS