"The odds of a person surviving that long of a flight at that altitude are very remote, actually. I mean, you are talking about altitudes that are well above the altitude of Mount Everest. And temperatures that can reach 40 degrees below zero. A lot of people would only have useful consciousness for a minute or two at that altitude. For somebody to survive multiple hours with that lack of oxygen and that cold is just miraculous. I've never heard of anything like that before."

Source: http://www.npr.org/blogs/thetwo-way/2014...