The NHS is preparing emergency plans to cope with summer heatwaves after last year's record temperatures killed thousands.

The NHS is preparing emergency plans to cope with summer heatwaves after last year's record temperatures killed thousands.

Hospitals will receive guidance later this month on how to prepare for an influx of patients suffering from the effects of heat.

The first "summer plan", similar to the routine "winter plan" to cope with flu epidemics, is being prepared by Professor Sir Liam Donaldson, the Chief Medical Officer.

During last year's August heatwave mortality rates leapt 17 per cent as thousands of mainly elderly people succumbed to heat-related conditions. The toll on the Continent, particularly in France, was much higher.

Although the Department of Health issued advice before the hottest day, there was no specific planning for increased NHS demand. Now hospitals and family doctors are to be placed on alert by the Met Office as soon as the temperature is forecast to hit 32C (90F) for two or more days.

The NHS will then be placed on one of four levels of alert, rising to an "emergency" footing when a prolonged heatwave threatens power and water supplies.

The warning should allow health managers to cope both with extra demand and expected staff shortages.

The new summer plan focuses particularly on care homes to ensure that vulnerable elderly people do not suffer needless discomfort.

Fierce heat not only increases the risk of heart and other existing conditions, it also prompts a surge of drink and drug-related accidents.

Extreme weather can also aggravate mental health conditions, overloading the health service when many medical staff are on holiday.

Between 4 and 13 August last year daily mortality rates rose by 17 per cent, with 2,000 more deaths than normal recorded. The victims were mainly over 75.

Temperatures peaked on 10 August with 38.5C (101.3F) recorded inKent. The Office for National Statistics estimates there were 1,691 deaths the following day, 363 more than the five-year average.

The pattern was repeated throughout the 10-day heatwave. Almost half of all deaths were recorded in the particularly hot South-east.

High night-time temperatures prevent people recovering from daytime heat. The new alerts will be triggered only if the thermometer fails to drop below 18C between hot days.

Britain escaped the worst effects of last year's heat. In France, President Jacques Chirac was forced to apologise for weaknesses in the country's health system that contributed to an estimated 10,000 preventable deaths.

The heatwave, judged by some experts to be a consequence of global warming, has concentrated minds in Whitehall.

The new NHS summer plan is one of a number of measures recommended by a cross-government group set up to plan for the effects of extreme weather. Others include plans for water shortages, power failures and disruption to food distribution.