Skeleton involves a person riding a small sled down a frozen track while lying face down. The sport is a more intense form of luge because skeleton competitors leap onto the sled and slide downhill head first. Skeleton athletes can reach up to 80 mph on straightaways, causing forces up to 5g, so the helmet is a critical component for attitude as well as safety.

A woman leaves sauna during the sauna marathon in Otepaa, Estonia on February 2, 2019. Participants have to track down, locate and visit designated saunas in the Otepaa area as fast as possible during the event. The team that completed all of the saunas in the shortest time wins. (Photo by Ints Kalnins/Reuters)

A tiger is painted on the backs of three models at the Three Lanes and Seven Alleys on January 3, 2012 in Fuzhou, China. (Photo by ChinaFotoPress/ChinaFotoPress)

Birds sit on the back of a zebra in the Nairobi National Park, near Nairobi, Kenya, November 21, 2018. (Photo by Baz Ratner/Reuters)

Heralds ride on horse-back through the streets of Moscow proclaiming the forthcoming coronation of Tsar Nicholas II, 1896. P.S. All pictures are presented in high resolution.

Children ride on the back of a truck at a camp for internally displaced people (IDPs) in Marib, Yemen on September 9, 2021. (Photo by Ali Owidha/Reuters)

A starling jealously guards a seed station in the back garden of the photographer’s Michigan home in January 2024. (Photo by Lisa Cavanary/Solent News)

A life-size robot named “Mark 1”, built by product and graphic designer Ricky Ma, 42, is seen in Hong Kong, China March 31, 2016. Ma, a robot enthusiast, spent a year-and-a half and more than HK$400,000 ($51,000) to create the humanoid robot, which is modelled after a Hollywood star, to fulfil his childhood dream. The eyes of the robot include face and color tracking functions. (Photo by Bobby Yip/Reuters)