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)

College students take shelter at a traffic point as a man paddles his rickshaw through a flooded road during heavy rain in Guwahati, India, June 13, 2017. (Photo by Anuwar Hazarika/Reuters)

In this photo taken on Thursday, September 6, 2018, a women releases an arrow during an archery competition during the Third Nomad Games, in Cholpon-Ata, 250 kilometers (156 miles) of Bishkek, Kyrgyzstan. The Central Asian nation of Kyrgyzstan held its biennial Nomad Games to promote and celebrate traditional sports of nomadic people. The week-long competition, which is held in a gorge near the picturesque Lake Issyk-Kul, feature traditional sports of nomad peoples such as horseback wrestling and goat polo. (Photo by Vladimir Voronin/AP Photo)

An American soldier walks ahead of an MKIV (Mark IV) British-made tank, circa 1918. (Photo by Hulton Archive/Getty Images)

A string art picture made by artist Ani Abakumova in a workshop in the village of Romashkovo in Moscow Region, Russia on August 2, 2019. Ani Abakumova and her husband Andrei Abakumov create string art replicas of famous paintings. Andrei makes computer calculations that show patterns for future images, then Ani winds coloured strings around nails hammered around a plywood board. (Photo by Anton Novoderezhkin/TASS)

A man holds his umbrella during snowfall on the Areopagitou pedestrian street beneath the Acropolis hill during snowfall in Athens, Greece, January 10, 2017. (Photo by Alkis Konstantinidis/Reuters)

Hillary Clinton waves to a selfie-taking crowd at a recent campaign event in Orlando, Florida on September 26, 2016. (Photo by Barbara Kinney/Hillary for America)