Participants of the 79th edition of the annual Christmas swimming “Coupe de Noel” jump into the Lake Geneva, in Geneva, Switzerland, Sunday, December 17, 2017. More than 2000 men and women swam the 120 meters at the traditional Christmas swimming in Geneva where the water temperature was 6 degrees. (Photo by Martial Trezzini/EPA/EFE/Rex Features/Shutterstock)

Journalists interview a girl, member of the Cryophile amateurs winter swimmers club, after bathing in the ice waters of the Yenisei River, during the celebrations for the upcoming Christmas and New Year, in Krasnoyarsk, Russia, December 23, 2017. (Photo by Ilya Naymushin/Reuters)

Chinese women wear face-kinis as they walk in to the water to swim at the beach on August 20, 2014 in the Yellow Sea in Qingdao, China. The locally designed mask is worn by many local women to protect them from jellyfish stings, algae and the sun's ultraviolet rays. (Photo by Kevin Frayer/Getty Images)

Hindu women worship the Sun god Surya in the polluted waters of the river Yamuna during the Hindu religious festival of Chatt Puja in New Delhi October 30, 2014. Hindu women fast for the whole day for the betterment of their family and the society during the festival. (Photo by Ahmad Masood/Reuters)

This is the amazing moment a heroic hippo saved a gnu from certain death. After being bitten by a crocodile, the large antelope is seen being dragged slowly under the water. But in a miraculous turn of events, a nearby hippo is seen making its way across the water to help the animal in its hour of need. Photo: One of the biggest hippos protects the gnu as it makes its way back to the shoreline, guarding it from any further attacks. (Photo by Vadim Onishchenko/Caters News)

Ukrainians swim in an ice hole as part of the celebration of the Epiphany in Kiev, Ukraine, Monday, January 19, 2015. Orthodox believers celebrate the holiday of the Epiphany on Jan. 19, and traditionally bathe in holes cut through thick ice on rivers and ponds to cleanse themselves with water deemed holy for the day. (Photo by Sergei Chuzavkov/AP Photo)

A competitor gestures as he crawls beneath barbed wire during the Tough Guy event in Perton, central England February 1, 2015. The annual event to raise cash for charity challenges thousands of international competitors in a cross country run followed by an assault course consisting of obstacles including water, fire and tunnels. (Photo by Phil Noble/Reuters)