Just a year after losing both of his legs, Warren was back climbing mountains again. He later became the first—and only—double above-the-knee amputee to climb the summit of Mount Kilimanjaro, one of the world's tallest peaks. "The outdoors has always been such a huge part of who I am," Warren says. "I got to the point where I thought, 'I wonder if it's possible for a guy with no legs to go back out into the mountains again.' I started training and I thought, 'If anybody's in a position to find out, it might as well be me.'"
He recounts his amazing survival and astounding comeback in his book, A Test of Will: One Man's Extraordinary Story of Survival.
Warren says losing both of his legs has not been an entirely bad experience. In fact, he says he does not even necessarily wish that it had never happened. "I've learned ... how infinitely more powerful each of us is, and how responsible we are for creating our reality," he says. "It wasn't in my reality—the same as it's not in most people's—for a guy with no legs to climb to the top of Kilimanjaro. So I set out to create that reality."