Long row of shiny new Flying Fortresses, part of huge reserves being built up in Britain for D-Day, stands by to be flown to combat units as replacements, May 25, 1944. (Photo by AP Photo)

A snail slithers up a rain spattered window during stormy weather on the Isle of Portland, Fortuneswell, England on July 29, 2018. (Photo by Stuart Fretwell/Rex Features/Shutterstock)

A dog dressed up for a show sits backstage during the 16th annual New York Pet Fashion Show on February 7, 2019 in New York City. (Photo by Johannes Eisele/AFP Photo)

Climate change activists dressed up as black birds protest in St. Ives, on the sidelines of the G7 summit in Cornwall, Britain, June 11, 2021. (Photo by Dylan Martinez/Reuters)

Children dressed up as Hindu Lord Krishna pose during Janmashtami festival celebrations marking the birth anniversary of Krishna in Agartala, India August 24, 2016. (Photo by Jayanta Dey/Reuters)

A Viet Cong suspect holds his hands up after a Vietnamese Ranger from the 21st Vietnam Infantry Division routed him from his hiding place. (Photo by Keystone/Getty Images). 7th November 1967

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.

Performers line up during the closing ceremony of the 2014 Winter Olympics, Sunday, February 23, 2014, in Sochi, Russia. (Photo by Darron Cummings/AP Photo)