Not sure if this is the right forum, but I honestly can't even remember the genre of the show I'm thinking of.
What I do remember: There was a shark attack of some sort. The guy barely survived. He was brought to a hospital, where the doctors noted that his heart rate was rapidly dropping, as if he was going into hibernation.
Yeah. That's about it. I have no clue what it was, but I want to find it. Any help?