UK residents may be gearing up for a summer that's more on-and-off than Lindsay Lohan's love life, but thanks to climate change the Met Office says steamy nights could soon become a killer.
The number of nights when the temperature in British cities remains above 20 degrees C will increase fivefold, a new report on climate change has found.
The study looked at the "urban heat island effect", caused when buildings and roads absorb heat during the day and release it at night, which leaves cities up to 10 degrees hotter than the surrounding countryside. Heat from cars, computers, lighting, machinery and cities' millions of inhabitants adds to the effect.
As a result of this temperature difference, on the hottest nights cities remain above 25 degrees – increasing the risk of heat exhaustion for the frail and elderly. The last major heatwave in Britain in 2003 claimed 2,000 lives, chiefly in urban areas.
Met Office researchers used computer simulations to examine how an expected rise in global temperatures would affect UK cities. Researchers found that the number of very hot nights each year in London would increase from two to ten by the year 2050.
Droughts like the one experienced by the UK in 1976, previously only expected every 50 to 100 years, could increase by as much as tenfold.
Vicky Pope, the head of climate advice at the Met Office, warned: "A two-degree rise in average temperatures may not sound very much, but there would be a much bigger rise in extreme temperatures on the hottest days and nights. We will need to adapt if we are to avoid the sort of serious impact we saw in 2003."
For a video view of global warming over the next century, click here.