Dr. John All got into a bit of a pickle when he was taking snow samples on his own on Mount Himlung - in Nepal's Himalayas. A glacier broke under him and he fell into a 70-foot crevasse. Needless to say, that kind of fall would kill most, but not John. He suffered multiple injuries but managed to escape using an ice pick.

He also caught the ordeal on film that lasted six hours. John is a geography lecturer from Western Kentucky University who specialises in mountain science.