A baby hippo swims under the water in its enclosure at Prague Zoo, Czech Republic, February 24, 2016. The baby was born on January 28, and is yet to be named. (Photo by David W. Cerny/Reuters)

An athlete dressed as a clown jumps into the Mediterranean sea as he takes part in the Copa Nadal in the Spanish port of Barcelona in Barcelona, Spain, Sunday, December 25, 2016. The Copa Nadal (Christmas Cup) is a traditional swimming competition that takes place in Barcelona every December 25th, where participants swim 200 meters in the open sea in the port of Barcelona. (Photo by Manu Fernandez/AP Photo)

Participants of the 77th edition of the annual Christmas swimming 'Coupe de Noel' jump into the waters of Lake Geneva, in Geneva, Switzerland, 20 December 2015. More than 1,540 men and women braved the water temperature of just 8 degrees Celsius as they swam a 120 meters distance at the traditional Christmas swimming in Geneva. (Photo by Salvatore Di Nolfi/EPA)

A swimmer disguised as Superman dives into the lake during the 78th “Coupe de Noel” (Christmas cup) swimming race in the Lake Geneva, on December 18, 2016 in Geneva. More than 1800 participants took part in the event, a 12-meter-long swimming off the Geneva's bank in the 7 degrees Celsius cold water. (Photo by Fabrice Coffrini/AFP Photo)

A woman wearing a swim suit skis during the Naked Pig Skiing Carnival at the Yabuli Ski Resort on March 24, 2018 in Harbin of Heilongjiang Province, northeast China. (Photo by Tao Zhang/Getty Images)

Members of a local winter swimming club photograph as they take part in festive bathing in the icy waters of Boyarskoye lake outside Tomsk, Russia, December 26, 2021. (Photo by Taisiya Vorontsova/Reuters)

Members of Brighton Swimming Club brave the early morning temperature to take a dip in the sea east of the pier on January 5, 2022. The club, founded in 1860, is the oldest in England. (Photo by Simon Dack/Alamy Live News)

A member of a winter swimming club wears flippers during the celebration of Maslenitsa, also known as Pancake Week, a pagan holiday, marking the end of the winter, in Novosibirsk, Russia. (Photo by Alexandr Kryazhev/Sputnik/Profimedia)