The Tough Guy Challenge is an endurance race in England. Thousands compete few finish. Over 600 people were treated for hypothermia as they made their way through freezing water on their way through 21 obstacles. The obstacles include crossing a rope course, crawling under barbed wire, mud pits and burning terrain.
I bet you weren't expecting to see an image like this today.
For being "the safest most dangerous taste of physical and mental endurance pain in the world" a lot of people were injured. Besides the hypothermia, racers suffered from dislocations, broken bones and exhaustion.
Plenty more pictures in the link above.