Four people in Romania died in high temperatures on Tuesday, according to health officials, taking the country's heat wave death toll to 29.
In western Turkey, a man collapsed on a beach and later died as temperatures there reached 44C.
Greece, which has seen some of the highest temperatures, is set to record its hottest ever June.
The Greek government has ordered all public offices to close at midday on Tuesday and Wednesday to allow people to stay out of the sun.
|Parts of the nothern England city of |
Sheffield were heavily flooded [Reuters]
Firefighters in Italy battled on Tuesday to bring 30 forest fires sparked by the heat wave under control, with their efforts frustrated by strong winds.
In Turkey, Muammer Guler, the governor of Istanbul, said pregnant and disabled public servants would be given days off on Tuesday and Wednesday.
Meteorologists said temperatures could hit 40C in the Romanian capital Bucharest on Tuesday, the highest level in 90 years.
In Britain, torrential rain and strong winds swept across England and Wales, killing three people and flooding homes and businesses.
A 68-year-old man drowned in flash flood waters in the northern city of Sheffield, while a man in his 20s drowned in Hull after becoming stuck in a drain.
A teenager also drowned in Sheffield after being swept away by the swollen River Sheaf.
About 250 people were evacuated from their homes near Rotherham, South Yorkshire, after cracks were spotted in the Ulley dam.
"For the people in the area concerned, those who need to be moved have been," Matthew Jukes, police commander for Rotherham, said.
Structural engineers were working to shore up the dam and pump out water from a reservoir covering more than 30 acres four miles south of the town.
"If the dam should burst we would be talking in terms of maybe 15 minutes or so before water would reach residential areas," said Mike Cuff, chief executive of Rotherham council.
Britian's environment agency has issued severe flood warnings in 20 areas, mainly in the Humberside, Lincolnshire, Yorkshire and Derbyshire districts.
The country's meterological office said the weather should improve on Tuesday.