A dune buggy driver trains before competing in a sand dune drag racing event on January 8, 2016, as part of the Liwa 2016 Moreeb Dune Festival in the Liwa desert, some 250 kilometres southwest of Abu Dhabi. The festival, which attracts participants from around the Gulf region, includes a variety of races (cars, bikes, falcons, camels and horses) or other activities aimed at promoting the country's folklore. (Photo by Karim Sahib/AFP Photo)

Fighters of the pro-government Popular Resistance Committees militia carry a cannon as they transport it in parts to Yemen's southwestern war-torn city of Taiz December 26, 2015. (Photo by Reuters/Stringer)

A member of the German wireless police picks up signals on the radio equipment he carries on his back, while his colleague takes notes. (Photo by General Photographic Agency/Getty Images). Circa 1925

Konishiki “The Dumptruck” of Hawaii stares down at his opponent during the first Sumo Bashai held outside Japan, at the Albert Hall in London, England. (Photo by Chris Cole /Getty Images). 1991

An ice swimming enthusiast dressed as Neptune takes to the frigid waters of Orankesee lake during the 27th annual "Winter Swimming in Berlin" on January 8, 2011 in Berlin, Germany. A local swimmers' group called the “Berlin Seals” invite ice swimmers from across Germany and abroad to the annual event. Members claim ice swimming is good for the body's blood circulation. (Photo by Sean Gallup)

A boy jumps from a swing during sunset in Valras-Plage, southern France December 29, 2014. (Photo by Yves Herman/Reuters)

A frozen public bench is seen next to a lake side due to the heavy wind conditions in Geneva February 8, 2015. (Photo by Pierre Albouy/Reuters)

Children play football in Bujumbura, Burundi on March 19, 2015. (Photo by Carl de Souza/AFP Photo)