Most of us were asleep on the other side of the world when Xia Boyu, a Chinese national reached the summit of Mt. Everest May 14. Impressive for anyone, but even more so for a sixty-nine-year-old double amputee. And, get this. This was Xia’s fifth attempt to scale the world’s highest peak, and it was on one of his earlier expeditions that he lost his lower legs to frostbite after lending his sleeping bag to…