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)

A donkey is seen before the start of the procession of the “Virgem da Atalaia” during Holy Week at Alcochete, near Lisbon April 5, 2015. Women ride donkeys during the “Virgem da Atalaia” procession, that has been held annually for about 400 years. In the past, only single women rode the donkeys to ask for help from the Virgin to find a husband. (Photo by Rafael Marchante/Reuters)

A tank's barrel is seen on the course of the Tank Biathlon competition during the International Army Games 2016 in Alabino, outside Moscow, Russia, July 30, 2016. (Photo by Maxim Zmeyev/Reuters)

Dancers attend a dress rehearsal for the new grand show “THE WYLD” at Friedrichstadt-Palast in Berlin October 2, 2014. Ten choreographers are working with 60 dancers from the world's largest show ballet company to create the flamboyant stage spectacle. The show's name, “THE WYLD”, represents human nature in its diversity and the wilderness of the big city – in this case, Berlin. The premiere of the 10.6 million euro ($13.5 million) show, the largest production budget in the 95-year history of Friedrichstadt-Palast, is on October 23, 2014. (Photo by Hannibal Hanschke/Reuters)

A gallery assistant poses with the 1972 work “Secretary” at a press viewing of the artist's exhibition “Allen Jones RA” at the Royal Academy of Arts in London November 11, 2014. (Photo by Neil Hall/Reuters)

Couples kiss during a kissing contest in Wuhan, Hubei province, November 23, 2014. Some 20 couples attended the contest and the winners have been awarded an iPhone 6, according to local media. (Photo by Reuters/Stringer)

Margaret Morris dancers exercising on the sands at Saint-Idesbald. (Photo by Fox Photos/Getty Images). August 1929

A to-do list written by John Lennon on display at the GOTTA HAVE IT! Rock & Roll Pop Culture Auction Press Preview at the Gotta Have It! store on November 30, 2011 in New York City. (Photo by Andy Kropa/Getty Images)