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 surfer rides a large wave at El Bocal during the Vaca Gigante (Big Cow) giant wave surf competition in Santander, northern Spain December 17, 2016. (Photo by Vincent West/Reuters)

Musician “Girli” poses for a portrait during London Fashion Week in London, Britain February 21, 2017. (Photo by Neil Hall/Reuters)

Shortlisted: Sólheimasandur aircraft crash site, Iceland by Ollie Conway. (Photo by Ollie Conway/Historic Photographer of the Year Awards 2019/The Guardian)

Kaitlin Hawayek and Jean-Luc Baker perform during the short dance program at the U.S. Figure Skating Championships in Greensboro, N.C., Friday, Jan. 23, 2015. (AP Photo/Chuck Burton)

A man wears a sweater covered in Irish themed pins as he stands with thousands of spectators to watch the 254th New York City St. Patrick's Day parade up 5th Avenue in the Manhattan Borough of New York, March 17, 2015. (Photo by Mike Segar/Reuters)

Actress Victoria Justice arrives at the 2011 MTV Video Music Awards at Nokia Theatre L.A. LIVE on August 28, 2011 in Los Angeles, California. (Photo by Christopher Polk/Getty Images)

In this photo provided by The Daily Free Press and Kenshin Okubo, people react to an explosion at the 2013 Boston Marathon in Boston, Monday, April 15, 2013. (Photo by Kenshin Okubo/AP Photo/The Daily Free Press)

P.S. All pictures are presented in high resolution.