A child looks at a polar bear swimming under a water in its enclosure on a hot summer day at Prague Zoo, Czech Republic, July 30, 2015. (Photo by David W. Cerny/Reuters)

A woman looks at a swimmer getting herself warm after the annual Christmas winter swimming competition in the Vltava river in Prague December 26, 2014. (Photo by David W. Cerny/Reuters)

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)

Swimmers take part in the annual Christmas Day swim in Porthcawl, Wales, England on December 25, 2019. (Photo by Ben Birchall/PA Images via Getty Images)

A toddler held by her father swims underwater during a swimming class for babies at Lane Cove pool February 16, 2007 in Sydney, Australia. (Photo by Ian Waldie/Getty Images)

In an observance of Epiphany, Russian Orthodox believers swim in an icy pond outside Nizhny Novgorod, Russia. (Photo by Olga “Zwezdochka”)

A man dressed in a Halloween costume swims along the coast of the northern Lebanese city of Batroun, on October 28, 2021. (Photo by Ibrahim Chalhoub/AFP Photo)