South Korea's Shim Sukhee falls in the women's 1,500m short track speed skating heat event during the Pyeongchang 2018 Winter Olympic Games, at the Gangneung Ice Arena in Gangneung on February 17, 2018. (Photo by Mladen Antonov/AFP Photo)

Athletes vie for the ball during the Mud Olympics in Brunsbuettel, Germany, 30 July 2016. Since 2004, amateur athletes have been competing in various events at the mouth of the Elbe river on the North Sea. The proceeds are traditionally donated to the Schleswig-Holstein Cancer Society. (Photo by Daniel Bockwoldt/EPA)

A sculpture is displayed at the Olympic Sculptures Exhibition at the Sculpture Park September 4, 2006 in Changchun of Jilin Province, China. (Photo by China Photos/Getty Images)

A reveller poses for a photo during the LGBT Pride Parade in Copacabana beach in Rio de Janeiro, Brazil, November 15, 2015. (Photo by Pilar Olivares/Reuters)

A dog dressed like of a bee is seen during the “Blocao” dog carnival in Rio de Janeiro, Brazil, Sunday, February 16, 2014. About 100 dogs have had their day at a pre-Carnival bash in Rio de Janeiro. A 10-man brass band and a singer belting out Rio's anthem song “Cidade Maravilhosa” (Marvelous City) kicked off the four-footed fest as dog owners gathered to party down with pooches on Copacabana beach Sunay. (Photo by Silvia Izquierdo/AP Photo)

Russia' s Tiffani Zagorski and Russia' s Jonathan Guerreiro compete in the ice dance free dance of the figure skating event during the Pyeongchang 2018 Winter Olympic Games at the Gangneung Ice Arena in Gangneung on February 20, 2018. (Photo by Lucy Nicholson/Reuters)

Japan' s Kaori Sakamoto competes in the women' s single skating short program of the figure skating event during the Pyeongchang 2018 Winter Olympic Games at the Gangneung Ice Arena in Gangneung on February 21, 2018. (Photo by John Sibley/Reuters)

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.