Swimmers known as the Lido Ladies pose by the pool during sunrise at Charlton Lido in Hornfair Park, London on December 2, 2020, on its first day of reopening after the second national lockdown ended and England enters a strengthened tiered system of regional coronavirus restrictions. (Photo by Victoria Jones/PA Images via Getty Images)

Visitors watch as members of a local winter swimmers club pour buckets of cold water over their daughters, 7-year-old Liza Broverman and 2-year-old Alisa Smagina during a celebration of Polar Bear Day at the Royev Ruchey zoo, with the air temperature at about minus 5 degrees Celsius (23 degrees Fahrenheit), in Krasnoyarsk, Russia, November 27, 2016. (Photo by Ilya Naymushin/Reuters)

A diver swims near sculptures during the inauguration of the underwater museum in Ayia Napa, Cyprus, 01 August 2021. At the new Ayia Napa Underwater Sculpture Museum (MUSAN), located in the Pernera area of Ayia Napa, visitors, both swimmers with mask and flippers and divers, will be able to tour around an underwater forest, the first of its kind in the world. (Photo by Jason Decaires Taylor/EPA/EFE)

A 40-foot sculpture of the swimmer Rebecca Adlington was unveiled at the Serpentine in London’s Hyde Park on July 25, 2016 to launch a campaign by Kelloggs to encourage the public to support Team GB at the Rio Olympics. (Photo by David Parry/PA Wire/Barcroft Images)

A swimmer reacts after finishing his competition in a pool carved into thick ice covering the Songhua River during the Harbin Ice Swimming Competition in the northern city of Harbin, Heilongjiang province January 5, 2015. The swimming competition was held on the official launch day of the Harbin International Ice and Snow Sculpture Festival. (Photo by Kim Kyung-Hoon/Reuters)

A swimmer stops short of a red algae bloom at Sydney's Clovelly Beach on November 27, 2012, which closed some beaches for swimming including Bondi Beach for a period of time. While the red algae, known as Noctiluca scintillans or sea sparkle, has no toxic effects, people are still advised to avoid swimming in areas with discoloured water because the algae, which can be high in ammonia, can cause skin irritation. (Photo by William West/AFP Photo)

This spiky tenrec was spotted in Madagascar’s Mantadia National Park in the last decade of September 2025. Mostly nocturnal and rarely seen, it puffs out its spines when threatened. Spiky tenrecs are excellent swimmers — unlike most spiny mammals, some species of tenrec can forage in streams and rivers, using their spines for protection while hunting aquatic insects and small prey. (Photo by Dale Morris/Solent News & Photo Agency)

An open water swimmer surfaces as she enjoys a socially-distanced dawn swim after breaking the ice on the surface of a lake near Scunthorpe, northern England, January 9, 2021. Faced by a sharp rise in coronavirus infections, driven by the new strain, England entered a strict lockdown on January 5, 2021, with schools and non-essential shops closed for at least six weeks after previous measures failed to halt the steep rise in cases. (Photo by Lindsey Parnaby/AFP Photo)