A diver dressed in a Santa Claus costume swims with a penguin at Sunshine Aquarium during preparations for the upcoming Christmas special event in Tokyo on December 1, 2025. (Photo by Kazuhiro Nogi/AFP via Getty Images)

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)

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)

Alex Sun, left, Peter Simplicio and Matt Connelly jump through a hole in the ice into Lake Andrews on the Bates College campus, Friday, February 9, 2024, in Lewiston, Maine. The annual Bates College Puddle jump started 50 years ago as a Winter Carnival tradition. (Photo by Andree Kehn/AP Photo)

Roman Cervenka #10 of Czechia celebrates with the trophy and gets a beer thrown on him from his teammates during IHF Ice Hockey World Championship gold medal celebrations with fans at Old Town Square on May 27, 2024 in Prague, Czech Republic. (Photo by RvS.Media/Monika Majer/Getty Images)

Allison Callender and Kent Willis, members of Mekanix Gym, a total wellness center, take a cold plunge in ice after a workout at the gym's Shadow Sanctuary facility during hot weather in Houston, Texas, U.S., July 19, 2023. (Photo by Adrees Latif/Reuters)

Japan's Riku Miura perform with Ryuichi Kihara, not seen, during the pairs free skating at the ISU Four Continents Figure Skating Championships at the Mokdong ice rink in Seoul, South Korea, Friday, February 21, 2025. (Photo by Lee Jin-man/AP Photo)

Weddell seal numbers in 2025 have declined sharply on Signy Island, part of the South Orkney Islands in the Southern Ocean, where British Antarctic Survey researchers have tracked seal populations for nearly 50 years to understand the impact of melting sea ice. (Photo by Michael Dunn/The Times)