Pamukkale, Turkey, is home to these terrace pools, formed by the build-up of carbonate mineral from the warm water flowing from the thermal springs above. (Photo by Image Courtesy of Jennifer Hayes/Getty Images)

A woman looks at a swimmer getting herself warm after the annual Christmas winter swimming competition in the Vltava river in Prague December 26, 2014. (Photo by David W. Cerny/Reuters)

“Warming up”. This photo I capture in the early afternoon, the animal species of lemurs fly. Photo location: Sambas, West Kalimantan, Indonesia. (Photo and caption by Hendy Mp/National Geographic Photo Contest)

Japanese monkeys snuggle to keep warm at a zoo in Tonosho in Kagawa Prefecture, western Japan on January 24, 2023. (Photo by Kyodo Photo via Newscom/Alamy Live News)

An athlete takes part in a warm-up around the track of the National Stadium in Tokyo on September 12, 2025, ahead of the World Athletics Championships. (Photo by Kirill Kudryavtsev/AFP Photo)

People try to keep warm their hands by a heater as they wait for their seats outside a restaurant at an outdoor shopping mall in Beijing, Saturday, December 23, 2023. A cold wave began earlier in the week bringing extensive snowfall and freezing temperatures across China. (Photo by Andy Wong/AP Photo)

Vendors warm themselves as they light a bonfire at a market during a nationwide power outage, in Muzaffarabad on January 23, 2023. A massive power breakdown in Pakistan on January 23 affected most of the country's more than 220 million people, including in the mega cities of Karachi and Lahore. (Photo by Sajjad Qayyum/AFP Photo)

In this Wednesday, August 20, 2014 photo released by Red Bull, Maikel Melero of Spain warms up prior to the fifth stage of the Red Bull X-Fighters World Tour in the South African savanna of Pretoria, South Africa. (Photo by Joerg Mitter/AP Photo/Red Bull)