PARIS: Europe sizzled under a continent-wide heatwave on Wednesday, with London bracing for Britain's hottest June day since 1976 as Portugal struggled to stamp out deadly forest fires.
More than 1,000 firefighters were still battling to control the flames that broke out in central Portugal at the weekend, killing at least 64 people.
Two forest fires have also broken out since Sunday on Croatia's southern Adriatic coast, prompting the authorities to evacuate 800 tourists, although the blazes have now been brought under control.
"We were scared, it's true," Swedish tourist Karolina told local media. "From the hotel room window it seemed like the fire was at our doors."
As the northern hemisphere marked the summer solstice -- the longest day of the year -- the mercury hovered around 35 degrees Celsius (95 degrees Fahrenheit) across oven-like swathes of Europe, including Italy, Austria, the Netherlands and even alpine Switzerland.
Firefighters were on alert in Austria, where revellers were set to mark the solstice by setting light to hundreds of bonfires to celebrate the festival of Saint John -- a tradition that goes on until the end of the month. Local authorities also announced a ban on barbecues in public parks, another popular tradition, to reduce the fire risk.
In Italy, forecasters say the current heatwave could turn out to be the most intense in 15 years, with temperatures around eight degrees above the seasonal average -- 39 degrees Celsius in Milan and up to 30 in the Alps at an altitude of 1,000 metres (3,300 feet).
A study released Monday warned that deadly heatwaves will become more and more common around the world even if the rise in temperatures is capped at 2.0 degrees C as targeted by the Paris Agreement to combat climate change.
"Even if we outperform the Paris targets, the population exposed to deadly heat will be about 50 percent by 2100," Camilo Mora, lead author of the study published in the journal Nature Climate Change, told AFP.
- London sizzles -
Britain was set to see its first five-day stretch of temperatures over 30 degrees C in June since 1995. The thermometer was forecast to hit 34 C in west London -- a record for the month since 1976.
In Guildford, southwest of the capital, a road surface melted on Tuesday, with motorists likening it to a a bar of chocolate left out in the hot sun.
At the prestigious Royal Ascot horse races, organisers said they were considering relaxing the strict dress code for the first time.
And a thunderstorm was looming over the Glastonbury Music Festival, threatening mud just as an expected 200,000 revellers begin pitching their tents.
Music lovers in France were also braving the heat, as the annual Fete de la Musique -- a nationwide celebration with thousands of free street performances -- kicked off under an official heatwave declared across swathes of the country.
Temperatures were due to peak Wednesday at 37 degrees in the Centre-Val de Loire area south of Paris, while a peak in pollution in the capital linked to the heat prompted police to reduce speed limits in some areas and divert heavy goods vehicles.
On Tuesday, the body of a 31-year-old man was pulled out of the Loire river after he got dragged down by the current while trying to cool down.
In Russia, Siberia was also suffering a heatwave, with temperatures of up to 37 C in the city of Krasnoyarsk, Channel One television reported.
But at the other extreme, it was just one degree Celsius and snowing in Murmansk in northern Russia, the RIA Novosti news agency reported. Many residents are having to get by with no heating in their flats as centralised systems have been switched off for the summer.