Finia, a visiting student from Hanover, cools off under a water sprinkler in front of the Chancellery on June 10, 2010 in Berlin, Germany. (Photo by Sean Gallup/Getty Images)

A high temperature alerts were issued as a record-setting summer heat wave continued to bake most parts of south China. (Reuters)

Tourists crowd a water park in Wuhan city, central China's Hubei province on July 15, 2017. Days of heat wave drove many citizens to the water park for fun and coolness. Nanchang has become the new four “furnace cities” in China according to a ranking of the hottest cities released by the China Meteorological Administration on July 9. (Photo by Imaginechina/Rex Features/Shutterstock)

A polar bear fast asleep at London Zoo. (Photo by Fox Photos/Getty Images). 1961

Two children jumping through a water hydrant's shower on a New York street. They have come from a neighbouring co-educational playgroup organised by the city's Police Department. (Photo by Orlando/Getty Images). 1950

A man jokingly poses with a new installation of British graffiti artist Banksy's art in New York, October 20, 2013. (Photo by Carlo Allegri/Reuters)

London Mayor Boris Johnson takes part in a tug of war with members of the armed services to launch the London Poppy Day, outside City Hall, in London, October 27, 2015. London Poppy Day is a street collection event to raise money for serving and retired members of the armed services and their families. (Photo by Stefan Wermuth/Reuters)

A worker sweeps leaves below a historic spirit still at Suntory Holdings' Yamazaki Distillery in Shimamoto town, Osaka prefecture, near Kyoto, December 1, 2014. Nestled at the foot of wooded hills near the ancient Japanese capital of Kyoto, the Yamazaki whisky distillery feels a long way from the northerly glens of Scotch's spiritual home. Despite its unlikely birthplace, last month Yamazaki's Single Malt Sherry Cask 2013 trumped more than a thousand challengers to be named the world's best whisky by leading critic Jim Murray in his Whisky Bible 2015. (Photo by Thomas Peter/Reuters)