The Mile O' Mud is a 7/8-mile oval track with a 1/8-mile diagonal lane slashed through the center. The racing lanes are approximately 60 feet wide. On average, the muddy water is four to six feet deep, with three strategically placed holes. The largest hole, located in front of the grandstand, is the treacherous “Sippy Hole”, named for the legendary driver “Mississippi” Milton Morris, Swamp Buggy King 1955, who repeatedly got stuck in it. (Photo by Malcolm Lightner)

A reveller participates in a flour fight during the “O Entroido” festival in Laza village, Spain February 27, 2017. (Photo by Miguel Vidal/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.

Revellers take part in the annual block party known as “Casa Comigo” (Marry Me), during carnival festivities in Sao Paulo, Brazil on February 15, 2020. (Photo by Rahel Patrasso/Reuters)

The mother (2nd R) of missing firefighter Xue Ning is helped by other family members as she cries outside the venue of a news conference after trying to demand for more information from government officials, following the explosions on Wednesday night at Binhai new district in Tianjin, China, August 15, 2015. (Photo by Jason Lee/Reuters)

Revelers participate in the traditional Bloco da Lama (Mud block) carnival in Parati, Rio de Janeiro State, Brazil, on February 9, 2013. The event, which was begun by two men in a playful manner in 1986, has now become a traditional carnival in which participants disguised as primitives with rags, lianas or skulls and bones, dive in the mud. (Photo by Victor Moriyama/AFP Photo)

The contest began in 2007, and since then photographers from more than 70 countries have entered. Photo: Michael O'Neal of San Francisco won first place in the animals category in the 2014 iPhone Photography Awards. (Photo by Michael O'Neal)