More than 400 people stripped off and ran into freezing waters to celebrate the autumn equinox – and raise money for charity at Druridge Bay, Britain, September 25, 2016. It was the largest turnout the North East Skinny Dip has ever seen in its five-year history, and it was also the first time it has ever rained on the morning of the event. Revellers gathered from 5.30am on Sunday at Druridge Bay, in Northumberland, before baring all in the North Sea. (Photo by David Charlton Photography)

A Sri Lankan activist, who wrapped himself with fire crackers, walks in Colombo on July 23, 2014 to symbolically demonstrate against people burned during Anti-Tamil riots on the island thirty-one years ago. Official accounts placed the death toll at 400 while human rights activists put the toll at thousands. (Photo by Ishara S.Kodikara/AFP Photo)

A firefighter battling the King Fire watches as a backfire burns along Highway 50 in Fresh Pond, California September 16, 2014. The fire led officials to call on about 400 people to evacuate from areas threatened by the blaze, Cal Fire spokeswoman Alyssa Smith said. It has charred more than 11,500 acres (4,654 hectares) and was 5 percent contained on Tuesday. (Photo by Noah Berger/Reuters)

An aerial view of rock salt collection pool made of tarpaulin, where rock salt is obtained by collecting the natural spring water in the mountains and evaporating the water, in Kozluk District of Batman, Turkiye on August 22, 2022. The production of rock salt, passed down from generation to generation, became the sole source of income for 45 households in the village of Derince, with a population of about 400 of Batman. (Photo by Omer Yasin Ergin/Anadolu Agency via Getty Images)

A Siberian tiger cub is seen at the Hengdaohezi Breeding Center for Felidae on October 26, 2007 in Harbin of Heilongjiang Province, China. Established in 1986, the breeding center is one of the world's largest captive breeding base for Siberian tigers. Distributed throughout northeastern China, far eastern Russia and North Korea, over 400 Siberian tigers exist in the wild, approximately 20 in China. (Photo by China Photos/Getty Images)

An aircraft passes the rising sun during take off at the international airport in Frankfurt, Germany, Monday, September 2, 2019. (Photo by Michael Probst/AP Photo)

Delta CEO Ed Bastian talks about the century-old airline's past and technology such as generative artificial intelligence that he sees shaping its future during a Consumer Electronics Show (CES) presentation at The Sphere concert venue in Las Vegas on January 7, 2025. Delta on January 7 marked a century of flying with visions of a future in which artificial intelligence and internet age partnerships make air travel fun and seamless. (Photo by Glenn Chapman/AFP Photo)

A flight crew from China Airlines, wearing protective masks, stand in the international terminal after arriving on a flight from Taipei at Los Angeles International Airport (LAX) on February 28, 2020 in Los Angeles, California. The World Health Organization (WHO) has raised the global coronavirus risk level to “very high”. (Photo by Mario Tama/Getty Images)