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 Palestinian woman paints a mural, depicting a masked Palestinian holding a knife, in support of Palestinians committing stabbing attacks against Israelis, in Rafah in the southern Gaza Strip November 3, 2015. (Photo by Ibraheem Abu Mustafa/Reuters)

A relic hunter dubbed “Indiana Bones” has lifted the lid on a macabre collection of 400-year-old jewel-encrusted skeletons unearthed in churches across Europe. Art historian Paul Koudounaris has hunted down and photographed dozens of gruesome skeletons in some of the world's most secretive religious establishments. Photo: Albertus in the church of St George in Burgrain, Germany. Incredibly, some of the skeletons, which took up to five years to decorate, were even found hidden away in lock-ups and containers. (Photo by Paul Koudounaris/BNPS)

Staff members work on sorting and assembling the skeleton of a fossilized Triceratops dinosaur, in Paris, France, 31 August 2021. The skeleton of a Triceratops, an over 66 million years old dinosaur, knicknamed “Big John”, will be auctioned at the Drouot Auction House on 21 October 2021 and is estimated to fetch a total of 1.5 million euros. (Photo by Christophe Petit Tesson/EPA/EFE)

A teller at a money changer handles Indonesia rupiah bank notes in Jakarta, Indonesia November 11, 2016. (Photo by Darren Whiteside/Reuters)

Visitors look up at mock-ups of dinosaur skeletons inside the Museum of Natural History in Pyongyang on September 28, 2016. (Photo by Ed Jones/AFP Photo)

Rescuers carry an injured passenger on stretcher at Soshigaya Okura Station after stabbing on a commuter train, in Tokyo Friday night, August 6, 2021. A man with a knife attacked 10 passengers on a commuter train in Tokyo on Friday and was arrested by police after fleeing, fire department officials and news reports said. (Photo by Kyodo News via AP Photo)