Cynthia the Kodiak Bear enjoys a whole Tasmanian Atlantic Salmon to celebrate her 28th birthday at Taronga Zoo on January 17, 2005 in Sydney, Australia. (Photo by Matt King/Getty Images)

Visitors watch as members of a local winter swimmers club pour buckets of cold water over their daughters, 7-year-old Liza Broverman and 2-year-old Alisa Smagina during a celebration of Polar Bear Day at the Royev Ruchey zoo, with the air temperature at about minus 5 degrees Celsius (23 degrees Fahrenheit), in Krasnoyarsk, Russia, November 27, 2016. (Photo by Ilya Naymushin/Reuters)

People wearing bear fur costumes dance during the annual bear ritual gathering in Comanesti, Romania, Friday, December 30, 2016. In pre-Christian rural traditions, dancers wearing colored costumes or animal furs, toured from house to house in villages singing and dancing to ward off evil, in the present the tradition has moved to Romania's cities too, where dancers travel to perform the ritual for money. (Photo by Vadim Ghirda/AP Photo)

Despite the high winds and fright temperatures, about 1/2 dozen brave members of the Coney Island Polar Bear Club took a dip in the Atlantic Ocean at March 14, 2017, just of Stillwell avenue in Coney Island beach in Brooklyn NYC. (Photo by Paul Martinka)

An environmental activist adjusts his mask while taking part in “The Dead Sea Swim Challenge”, swimming from the Jordanian to Israeli shore, to draw attention to the ecological threats facing the Dead Sea, in Kibbutz Ein Gedi, Israel November 15, 2016. Swimmers from around the world plunged into the salty waters of the Dead Sea on Tuesday to attempt a seven-hour swim across the fabled lake in a bid to draw attention to its environmental degradation. Wearing protective masks and snorkels, 25 swimmers paddled through the muddy water to attempt the 9-mile (15-kilometer) swim from Jordan to Israel. (Photo by Nir Elias/Reuters)