Participants compete in the Mud Day Race extreme run competition at El Goloso military base, outside Madrid, Spain, June 11, 2016. Thousands of athletes got covered in mud as they celebrated International Mud Day running a 13-kilometer obstacle course on a sunny Saturday with heatwave-like temperatures up to a 29 degrees Celcius (around 84 degrees Fahrenheit). (Photo by Juan Medina/Reuters)

Clashes break out in the stands during the Euro 2016 Group B soccer match between England and Russia, at the Velodrome stadium in Marseille, France, Saturday, June 11, 2016. (Photo by Thanassis Stavrakis/AP Photo)

Residents carry an injured woman rescued from a collapsed house in Funing county in Yancheng city of eastern China's Jiangsu Province on Thursday June 23, 2016. A powerful tornado hit Thursday, with reports of dozens killed and large numbers of buildings destroyed in the eastern Chinese province of Jiangsu, according to state media. (Photo by Chinatopix via AP Photo)

Araya A. Hargate, nickname Chompoo poses on the red carpet for the screening of the film “Les Miserables” during the 72nd annual Cannes Film Festival on May 15, 2019 in Cannes, France. (Photo by Stephane Mahe/Reuters)

A huge colony of Pacific Walrus on Arakamchechen Island in the Northern Bering Sea. (Photo by Francois Gohier/Ardea/Caters News)

Josef Tödtling – Longest duration full-body burn (without oxygen) Guinness World Records 2016. Location: Styria, Austria. (Photo by Richard Bradbury/Guinness World Records)

“After an afternoon of hiking and exploring the caves of Rhossili Bay, West Glamorgan, we caught the sun breaking through the clouds”. (Photo by Megan Warren-Davis/The Guardian)

National Geographic has created “Air, Land & Sea: the 50 greatest wildlife photographs” exhibition. Here: CT4 Crocodile cave on the Salamat river. Set up with Nathan Williamson last chip rain came while we were with the nomads. (Photo by Michael Nichols/National Geographic)