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)

In this October 14, 2013 photo, ecology professor Ricardo Freitas catches a broad-snouted caiman to examine, then release back into the water channel in the affluent Recreio dos Bandeirantes suburb of Rio de Janeiro, Brazil. Caimans are like tanks, a very old species with a remarkable capacity for renovation that allows them to survive under extreme conditions where others couldn't, said Freitas, who runs the Instituto Jacare, or the Caiman Institute, which aims to protect the reptiles. (Photo by Felipe Dana/AP Photo)

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.

Japan' s Kaori Sakamoto competes in the women' s single skating short program of the figure skating event during the Pyeongchang 2018 Winter Olympic Games at the Gangneung Ice Arena in Gangneung on February 21, 2018. (Photo by John Sibley/Reuters)

Rescuers work at the traffic accident site on April 1, 2011 in Xi'an, Shaanxi province of China. A truck collided with a bus at a cross on Friday morning. As the truck headed for the sidewalk, it collided into a pedestrian and 6 vehicles which were stopped nearby. As a result 16 people were injuried, one currently has severe injuries. (Photo by ChinaFotoPress/Getty Images)

In this Wednesday, March, 5, 2014 photo, Afghan female boxers practice at the Kabul Stadium boxing club, Afghanistan. The women, who are 18 and older, don't have much more than determination, and a trainer who runs them through their paces, watches as they spar, corrects their technique, tells them when to jab, how to protect themselves, when to power through with a left and then a right. (Photo by Massoud Hossaini/AP Photo)

Giant Olympic rings are towed on The River Thames past The Tower of London on February 28, 2012 in London, England. (Photo by Peter Macdiarmid/Getty Images)