“The Tonight Show” host Jimmy Fallon, center, exits the water during the Chicago Polar Plunge, Sunday, March 2, 2014, in Chicago. Fallon joined Chicago Mayor Rahm Emanuel in the event. (Photo by Andrew A. Nelles/AP Photo)

Crown line handler Bobby Marie controls “Chain Gang” as the balloon is inflated during the 43nd Annual Helen to the Atlantic Balloon Race and Festival, in Helen, Georgia, USA, 04 June 2016. The race is the oldest balloon event in the southern USA and United States' only long-distance hot air balloon race, according to the organizers. (Photo by Erik S. Lesser/EPA)

A Palestinian female masked militant from the Al-Quds Brigades, the military wing of the Islamic Jihad, takes part in an Islamic Jihad rally in Rafah, southern Gaza Strip, 29 July 2016. (Photo by Mohammed Saber/EPA)

A monument to the character of Darth Vader from "Star Wars", which was rebuilt from a statue of Soviet state founder Vladimir Lenin, is seen in Odessa, Ukraine, October 23, 2015. The Internet Party of Ukraine's main candidate, a person named for the legendary "Star Wars" villain Darth Vader, campaigned in Odessa, cruising through town on a black van to the sound of Imperial March from "Star Wars" saga. (Photo by Yevgeny Volokin/Reuters)

A guide dangles a live chicken in front of a crocodile in the village of Bazoule, Burkina Faso, December 4, 2015. The villagers believe the crocodiles that live there are sacred. (Photo by Joe Penney/Reuters)

A visitor feeds a food pellet to a giraffe in the Giraffe Centre in Nairobi, Kenya January 15, 2017. (Photo by Goran Tomasevic/Reuters)

A participant prepares for the Red Bull Air Race World Championships in Abu Dhabi, United Arab Emirates on February 6, 2017. (Photo by Red Bull Content Pool/SIPA Press/Rex Features/Shutterstock)

St Andrews University students skinny dip in the sea as May Day celebrations in St Andrews, Scotland on April 30, 2017. Hundreds of revellers ditched their clothes and bravely jumped into the bitterly cold North Sea. (Photo by Alamy Stock Photos)