Take a siesta to beat the British heat

The Sunday Times
March 1, 2009
Jonathan Leake, Science and Environment Editor

TAKE cover: heat waves are on the way. Despite the unusually cold winter the government has drawn up a national emergency plan to deal with the rising risk of extreme hot weather linked to climate change.
Under the plan, people in areas hit by heat waves will be advised to stay indoors during the middle of the day — in effect, taking a siesta — and change out of formal clothing such as suits and avoid hot food.
They will also be advised to stay cool by using fans, shading windows and drinking lots of water.
The “siesta alert” system has been prepared by the Department of Health in consultation with other agencies. One of them is the Met Office, whose scientists have warned that climate change means heat waves will become ever more frequent over the next two decades and will turn into regular events after 2030.

“The heat wave that hit France in 2003 caused an extra 35,000 deaths,” said Wayne Elliott, head of health forecasting at the Met Office. “Such events are likely to happen more often and become longer and more extreme as climate change takes hold.They are a serious threat to health”
The highest temperature measured in the UK, 38.5C, was recorded at Faversham in Kent on August 10, 2003. The Met Office warns that this might become a normal summer’s day by the 2080s.
On Friday the Met Office hosted a private conference for governmental agencies and public health experts, who discussed the emergency plan.
It envisages setting up a national response centre overseen by the Cabinet Office whenever a prolonged heatwave threatens. This would send out public alerts and co-ordinate responses by councils, local authorities and emergency services.
This is the same “Cobra” system that already handles major national emergencies such as flooding or outbreaks of animal diseases such as foot and mouth.
The aim would be to bring about rapid changes in people’s behaviour, including staying indoors between the hottest time of the day peak heat hours of 11am - 3pm, swapping suits for casual loose-fitting clothes and avoiding hot food.
The Met Office also plans to work with GPs to directly target those most at risk from prolonged heat. This would include the elderly and people with medical conditions such as circulatory and heart disease.
They would be issued in advance with personalised heat wave health packs by their GPs. Then, when a heat wave threatened, they would get automated warning telephone calls reminding them to re-read their health advice, check medication and contact their doctors if necessary.
A similar system has already been deployed by the Environment Agency to deliver warnings of floods to people in areas at risk of inundation.
Professor Robert Maynard, head of the air pollution unit at the Health Protection Agency, an expert in climate change impacts on health,said heat waves could kill thousands of people a year unless Britain was prepared. He said:“Elderly people suffer most. Their physiology means they are less able to lose heat through sweating. Eventually they can suffer heart failure.
“If people know what to do, however, they can stay cool by using fans, wet sponges, shading windows and drinking lots of water.”
“People in Southern Europe achieve this largely by changing behaviour, such as use of shade, fans, and avoidance of exercise. They also become physiologically adapted. In Britain the focus has to be on behavioural change because of the rapid onset of heat waves.
The new Heatwave Plan, to be published later this year, will also focus on residential and nursing homes for the frail elderly who are particularly at risk from prolonged heat.
Such establishments will be expected to record temperatures four times a day during a heat wave and to set up cool rooms equipped with air-conditioning into which residents can be moved should temperatures rise above 26C.
One oddity is that the definition of what constitutes a heat wave varies around the country.
In London a heat wave is only declared when daytime temperatures reach 32C, falling to no less than 18C at night. In the north-east, however, daytime temperatures only need to reach 28C, falling to no less than 15C at night., for a heat wave to be declared.
Studies show that, as temperatures rise, people living in northerly climes start dying at less extreme heat than those in London and the south-east, who are physiologically better adapted to heat.
Heat waves are not a new phenomenon - Britain has experienced at last seven of them in the last 40 years. They are, however, becoming more frequent and hotter.
The most extreme conditions are, however, likely to occur in cities like London, Manchester and Birmingham where the so-called urban heat island effect can already push temperatures up to 9C higher than the surrounding countryside.
This is partly due to the vast amounts of energy expended in lighting, heating and transport in cities - all of which eventually turns into heat.
Under the plan, the government would also encourage people to walk or cycle during heat waves to reduce the heat generated through cars, buses and trains.
The Heatwave Plan also includes longer-term proposals for helping Britain adapt. to prolonged high temperatures. These include planting more trees around public buildings and homes to generate shade, painting public buildings with reflective paint and promoting the wider use of loft and wall insulation.
Research has shown that prolonged high temperatures can have indirect effects on health too, for example by promoting the formation of highly toxic atmospheric pollutants such as ozone. They can also change people’s behaviour - murder and suicide rates both increase in heat waves.
Met Office Climate Change website
Tyndall Centre for Climate Change