A young girl cools off from the heat at “Grugabad” open-air swimming pool on a hot summer day in Essen, Germany, June 30, 2015. A widespread, long-lasting heat wave will spread across much of France, U.K., Belgium, the Netherlands and western Germany with forecast highs on Wednesday reaching 35 degrees Celsius (95 degrees Fahrenheit). (Photo by Ina Fassbender/Reuters)

Paul, 9, dumps a bucket of water over his head at a fountain near government buildings during hot weather on July 1, 2015 in Berlin, Germany. Temperatures across northern Europe are rising and in Germany a high of 36 degrees is forecast for the weekend. (Photo by Sean Gallup/Getty Images)

People stand on water slide platform at “Grugabad” open-air swimming pool on a hot summer day in Essen, Germany, June 30, 2015. (Photo by Ina Fassbender/Reuters)

A young woman plays in a fountain on a hot Summer day in London, Britain July 1, 2015. (Photo by Paul Hackett/Reuters)

Children play in a fountain on a hot Summer day in London, Britain July 1, 2015. (Photo by Paul Hackett/Reuters)

Boys jump into the Works Swimming Pool in the yard of the former coking plant of the Zeche Zollverein UNESCO world heritage site in Essen, Germany, July 1, 2015. The Works swimming pool created by the two Frankfurt artists Daniel Milhonic and Dirk Paschke is made of two regular ship containers. The 13 by 5 m long, 2.4 m deep pool is open during the summer and admittance is free of charge. (Photo by Wolfgang Rattay/Reuters)

A tourist with a hat visits Madrid's landmark Plaza Mayor during a hot summer day in central Madrid, Spain, July 1, 2015. (Photo by Andrea Comas/Reuters)

Children collect water at a public fountain at the Louvois square on a hot summer day in central Paris, France, July 1, 2015. A widespread, long-lasting heat wave will spread across much of France, U.K., Belgium, the Netherlands and western Germany with forecast highs on Wednesday reaching 35 degrees Celsius (95 degrees Fahrenheit). (Photo by Charles Platiau/Reuters)

A woman enjoys the sun along the banks of River Seine on a hot summer day in Paris, France, July 1, 2015. (Photo by Charles Platiau/Reuters)

People cool off in the Trocadero fountains during a hot summer day in Paris, France, July 1, 2015. (Photo by Charles Platiau/Reuters)

A woman sunbathes on a beach along the Bassin d'Arcachon Sea during a warm and sunny day in Arcachon near Bordeaux, southwestern France, July 1, 2015. (Photo by Regis Duvignau/Reuters)

A man dives from a jetty into the Bassin d'Arcachon Sea during a warm and sunny day in Arcachon near Bordeaux, southwestern France, July 1, 2015. (Photo by Regis Duvignau/Reuters)

Maria Romana from Spain poses for photographers as she cools off in a fountain on a hot Summer day in London, Britain July 1, 2015. (Photo by Paul Hackett/Reuters)

A man dives from a jetty into the Bassin d'Arcachon Sea during a warm and sunny day in Arcachon near Bordeaux, southwestern France, July 1, 2015. (Photo by Regis Duvignau/Reuters)

A group of swimmers play on a climbing wall in the water of the Bains des Paquis on a hot summer day in Geneva, Switzerland, July 1, 2015. (Photo by Pierre Albouy/Reuters)

A woman fans herself while waiting for a train on the London underground on a hot day in London, July 1, 2015. Temperatures in London hit 34.5 degree Celsius (94 degree Fahrenheit) by lunchtime, making it the hottest day in July in nine years in Britain. (Photo by Paul Hackett/Reuters)

Hadley Eames covers Gemma Cousins with stones as they sunbathe on a hot Summer day at Brighton beach in Britain June 30, 2015. (Photo by Luke MacGregor/Reuters)

Lukas and Rosa enjoy the refreshing fountain in Southbank, London, Wednesday, July 1, 2015. Britain is preparing itself for the hottest day in nine years Wednesday, with temperatures possibly rising to 35 Celsius (95 Fahrenheit) in London. (Photo by Frank Augstein/AP Photo)

A woman swims in an outdoor swimmingpool while the sun is shining in Hamburg, Germany, July 1, 2015. The European weather forecast is predicting high temperatures for the next few days. (Photo by Axel Heimken/EPA)