We were just discussing that at work
His is truly an exceptional and remarkable case. I hope he recovers without any permanent damage, but that may be asking a lot. It sounds like he was in pretty bad shape when they found him.
When it comes to survival in difficult conditions, no one really knows what the limits of human endurance are. We were discussing it in terms of children being revived after being submerged in cold water for up to 45 minutes or so. There's a thing called the Mammalian Diving Reflex involved that's fascinating, if perhaps controversial.