Children watch their classmate pour cold water on herself under the watch of a fitness coach at a local kindergarten in Russia's Siberian city of Krasnoyarsk, March 11, 2015. The program, which also involves sports training and sauna usage, has been practiced by the kindergarten for more than 15 years as they believe it has health benefits and keeps the children fit. Children start pouring cold water on themselves outdoors after about three years of training and undergoing medical tests, and the kindergarten is the only one in the region that practices these exercises, according to employees. (Photo by Ilya Naymushin/Reuters)

Zhang Shifan's sixth-generation facekinis in Shandong Province, Qingdao, East China. A woman credited with inventing the bizarre swimwear known as the “facekini” has now proudly presented the sixth generation of the iconic beach clothing. The new facekini models are not only more comfortable, they also come in a wider variety of colours and patterns, bringing both style and practicality to beach-goers in Qingdao City, in East China's Shandong Province, who fear tan lines. (Photo by CEN)

India's Central Reserve Police Force personnel take part in a rehearsal for the Republic Day parade on a cold winter morning in New Delhi January 8, 2014. (Photo by Ahmad Masood/Reuters)

A woman in costume checks her phone at the Star Wars Celebration convention in Anaheim, California, April 16, 2015. The Star Wars Celebration runs through April 19 at the Anaheim Convention Center. (Photo by David McNew/Reuters)

A skydiver dressed as Santa Claus prepares to leap out of a plane as 155 tandem skydivers set a new Guinness World Record over eight hours, over the Australian city of Wollongong, December 17, 2016. (Photo by Jason Reed/Reuters)

British South American Airways hostess Mary Guthrie with a pair of pineapples, on the return of the Lancastrian airliner 'Star Dust' to Heathrow Airport after a test-flight to Buenos Aires, 15th January 1946

A young arab boy, armed with a rifle and a knife, in the Aden Protectorate near Yemen. (Photo by Richards/Fox Photos/Getty Images). February 1938

Revellers celebrate "Ash Monday" by participating in a colourful "flour war", a traditional festivity marking the end of the carnival season and the start of the 40-day Lent period until the Orthodox Easter,in the port town of Galaxidi, some 215 km (134 miles) north west of Athens, March 18, 2013. The revellers "fight" by throwing coloured flour, charcoal dust and powder painting until they essentially run out of supplies. (Photo by Yannis Behrakis/Reuters)