People swim underwater at Clovelly Beach on December 14, 2023 in Sydney, Australia. A severe heat wave hit Sydney over the weekend, a precursor of hot and dry conditions expected for the rest of the summer which will also bring heightened bushfire risk. The mercury rose to alarming levels again on Thursday. (Photo by Jenny Evans/Getty Images)

Matilda Thurston 10, enjoys a warm day at Hathersage Swimming Pool in Hathersage on April 27, 2025. A mini heatwave is set to hit parts of the UK with temperatures reaching 27 degrees next week. (Photo by Ioannis Alexopoulos/London News Pictures)

Zoi Karangelou of Greece compete in the Women's Solo Technical final on day one of World Aquatics Artistic Swimming World Cup Super Final 2025 at Xi'an Olympic Sports Centre on June 13, 2025 in Xi An, China. (Photo by Lintao Zhang/Getty Images)

Several beaches along South Florida's Atlantic coast line were closed after thousands of sharks were seen migrating in the waters. The sharks were migrating from Boca Raton to Jupiter since the beginning of March, marine biologists told NBC Miami. Photo: A spinner shark swims just offshore on Midtown Beach in Palm Beach on Tuesday. (Photo by Jeffrey Langlois/Palm Beach Daily News)

A South Korean diver clad in Santa Claus costume swims with sardines at The Coex Aquarium on December 8, 2012 in Seoul, South Korea. Even though the official religion of South Korea is Buddhism, about 30 percent of it is Christian and Christmas is one of the biggest holidays to be celebrated in South Korea. (Photo by Chung Sung-Jun)

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)

National Diving School director Jerome Vincent, wearing a Gandolfi space suit, executes training procedures in a swimming pool in Marseille October 22, 2014. The underwater test session develops European expertise in spacewalk simulations under partial gravity for exploring the Moon, asteroids and Mars.The training is organised by Comex, a French company specializing in engineering and deep sea diving operations, in collaboration with the European Space Agency (ESA) and with Apollo XI “Under the sea”. (Photo by Jean-Paul Pelissier/Reuters)

A group of people wearing Santa Claus hats and swimming suits participate in the 13th charity Great Santa Claus Run in downtown Budapest, Hungary, Sunday, December 11, 2016. (Photo by Balazs Mohai/MTI via AP Photo)