A sun bear reacts to triple-digit temperatures at the Henry Doorly Zoo in Omaha, Nebraska, where the temperature reached 103 degrees Fahrenheit on July 6, 2012. (Photo by Nati Harnik/Associated Press)

Men dressed as soldiers pose with models before the opening of the Gamescom 2013 fair in Cologne,Germany, on August 23, 2013. The Gamescom convention is Europe's largest video games trade fair. (Photo by Ina Fassbender/Reuters)

Elementary school children play outside their classrooms as mount Sinabung volcano spews thick volcanic ash in the background on February 10, 2017 in Karo, Indonesia. Mount Sinabung is one of the most active volcanoes in Indonesia and last erupted in May 2016, killing seven people. (Photo by Albert Damanik/Barcroft Images)

A singer drinks from a huge bowl of beer on-stage as he pays tribute to the customers after performing at an entertainment club in Beijing, on May 8, 2014. (Photo by Jason Lee/Reuters)

High angle view of a young woman reading in a bathtub, turning page, enjoying time with herself. Candles and red wine. Valentines day concept, International womans day. (Photo by Vuk Saric/Getty Images)

A monkey is led by its trainer Qi Defang during training for a circus in Suzhou, Anhui province, November 29, 2014. Suzhou is known as the hometown of circus troupes in China and has more than 300 circus troupes. (Photo by William Hong/Reuters)

A street performer jumps in the air inside Central Park as the colors of autumn become more prevalent in New York, October 29, 2015. (Photo by Lucas Jackson/Reuters)