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)

National Geographic photographer Steve Winter has spent most of his adult life shooting wild cats. Photo: A 14-month-old cub, cooling off in a pond, is riveted by a deer that appeared near the shore. Tigers are powerful swimmers; they can easily cross rivers four to five miles wide and have been known to swim distances of up to 18 miles. (Photo by Steve Winter/National Geographic)

Snorkelers interact with a Florida Manatee inside of the Three Sisters Springs in Crystal River, Florida January 15, 2015. On winter days, Florida manatees flock by the hundreds to the balmy waters of Three Sisters Springs, drawing crowds of snorkelers and kayakers to the U.S. sanctuary, where people may swim with the endangered species. But as tolerant as the gentle, whiskered sea giants can be of the accidental kicks and splashes of delighted tourists, wild life regulators want to ban most canoes and paddle boards and create people-free zones to protect the wintering “sea cow”. Proposed limitations for this winter are awaiting approval by the U.S. Fish and Wildlife Service. (Photo by Scott Audette/Reuters)

Naked riders seen participating during the World Naked Bike Ride to demonstrate the vulnerability of cyclists on city streets in London, United Kingdom on June 9, 2018. People chose to ride naked to celebrate cycling and body freedom. (Photo by Brais G. Rouco/SOPA Images/LightRocket via Getty Images)

Swans swim over a lake, with the air temperature at about minus 35 degrees Celsius (minus 31 degrees Fahrenheit) as steam ascends above the water during sunset near the village of Urozhainy, Sovetsky district of Altai region, January 26, 2015. About 600 swans annually migrate to the lake, which is heated by warm springs, where they spend their winter being fed by yagers, which helps them to survive the severe cold. (Photo by Andrei Kasprishin/Reuters)

Naked cyclists wearing masks, ride through the streets of Mexico City during the World Naked Bike Ride day, Saturday, June 11, 2022. (Photo by Eduardo Verdugo/AP Photo)

Naked Sushi event where people eat sushi from the bodies of nearly naked models at Buddha Bar, Knightsbridge in London, United Kingdom. (Photo by Alamy Stock Photo)

A naked holy man pulls a vehicle using his pen*s during the Magh mela festival in Allahabad, India on January 3, 2018. (Photo by Prabhat Kumar Verma/ZUMA Wire/Rex Features/Shutterstock)