Apple CEO Tim Cook discusses the new iPhone 6 and iPhone 6 plus on Tuesday, September 9, 2014, in Cupertino, Calif. The iPhone 6 will have a screen measuring 4.7 inches, while the iPhone 6 Plus will be 5.5 inches. (Photo by Marcio Jose Sanchez/AP Photo)

Katy Perry attends the 2019 Met Gala celebrating “Camp: Notes on Fashion” at the Metropolitan Museum of Art on May 06, 2019 in New York City. (Photo by Andrew Kelly/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.

Members of the Communist New Fourth Army on parade. Note how the modern equipment contrasts with the shoeless soldiers in the foreground. (Photo by Hulton Archive/Getty Images). 6th July 1946

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

Kylie Jenner attends the 2019 Met Gala celebrating “Camp: Notes on Fashion” at the Metropolitan Museum of Art on May 06, 2019 in New York City. (Photo by Andrew Kelly/Reuters)

The ex-Pussycat Doll Nicole Scherzinger climbed 1,000-plus steps of an old Honolulu railway line in Hawaii in the first decade of January 2023. (Photo by Instagram)

American plus-sized model and television presenter Ashley Graham in the last decade of May 2023 wore black lingerie under her shimmering Prada look for a party in Cannes. (Photo by ashleygraham/instagram)