Alessandra Ambrosio arrives for the screening of “The Dead Don't Die” and the Opening Ceremony of the 72nd annual Cannes Film Festival in Cannes, France, 14 May 2019. Presented in competition, the movie opens the festival which runs from 14 to 25 May. (Photo by Ian Langsdon/EPA/EFE)

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.

Emma Watson poses at the winners boards at the Sony Ericsson Empire Film Awards at the Grosvenor House Hotel on March 9, 2008 in London England. (Photo by Dan Kitwood/Getty Images)

A man walks on the Cobb as storm waves break behind on December 13, 2011 in Lyme Regis, England. (Photo by Matt Cardy/Getty Images)

NASA's DHC-3 Otter plane flies in Operation IceBridge-Alaska surveys of mountain glaciers in Alaska in this image released on September 18, 2014. Over the past few decades, average global temperatures have been on the rise, and this warming is happening two to three times faster in the Arctic. (Photo by Chris Larsen/Reuters/NASA/University of Alaska-Fairbanks)

A woman wearing cut-off jeans and a halter-neck sun top in St Tropez, 1972. (Photo by Roy Jones)

The graffiti against the war in Ukraine of the street artist ChemiS in Prague, Czech Republic, March 19, 2022. (Photo by Amos Chapple/Radio Free Europe/Radio Liberty)

Activists from the People for the Ethical Treatment of Animals (PETA) demonstrate with slogans in protest of the designers use of fur, during the Paris Fashion Week, in front of the Eiffel Tower, in Paris, France, September 25, 2018. Placards read: “For a Fashion Week without fur”. (Photo by Benoit Tessier/Reuters)