Swimmers climb out of a pool carved into the thick ice covering the Songhua River during the Harbin Ice Swimming Competition in the northern city of Harbin, Heilongjiang province January 5, 2014. According to organisers, about 700 swimmers across China took part in the event on the official launch day of the Harbin Ice and Snow Sculpture Festival. (Photo by Kim Kyung-Hoon/Reuters)

A female swimmer reacts after finishing the competition in a pool carved from thick ice covering the Songhua River during the Harbin Ice Swimming Competition in the northern city of Harbin, Heilongjiang province, January 5, 2016. The swimming competition was held on the official launch day of the Harbin International Ice and Snow Sculpture Festival. (Photo by Aly Song/Reuters)

A model walks down the runway during the Fashion Palette Miami Australian Swim Show during Miami Swim Week, Sunday, July 15, 2018, in Miami Beach, Fla. (Photo by Lynne Sladky/AP Photo)

Photographs show an adventurer swimming with giant Manta Rays at night. In her latest daring adventure, Alison Teal set out in the middle of the night to free dive with Manta Rays off the coast of Hawaii. Using only hand held dive lights, Alison dove over 50 feet down being careful never to touch the mantas as they fed off the plankton in the light streams. Here: Photos taken by photographer Sarah Lee show the beautiful sight of Manta Rays at night, as they swim with America explorer, Alison Teal. (Photo by Sarah Lee/Caters News Agency)

Iraqi teenagers swim in waste water from the nearby Tuweitha nuclear facility near Baghdad, Iraq on May 28, 2003. Iraqis are consuming contaminated water unaware of the dangerous pollutants that can cause severe ill health. (Photo by Damir Sagolj/Reuters)

A competitor dressed up as Santa Claus jumps into the sea during the 102nd Barcelona Traditional Christmas Swimming Cup at the Old Harbour of Barcelona on December 25, 2011 in Barcelona, Spain. (Photo by David Ramos/Getty Images)

Swimmers in fancy dress splash as they participate in the New Year's Day Loony Dook swim at South Queensferry, Scotland January 1, 2015. (Photo by Russell Cheyne/Reuters)