
He also could have stayed in the elevator. The guy really doesn't care about his life too much. Not to mention that the entire area was littered with insulated rooms complete with generators and heat sources that warm Isaac up almost instantly. I suppose he could have accepted his death and not want to delay the inevitable, but come on! I mean, there were blankets in the room, and he didn't think of wrapping himself in them? Improvising a suit with them? Or building a shelter with them? Really, anything but just sit in a corner and wait to freeze to death. The problem is, he didn't seem to care for his well-being much afterwards. After crashing on Tau Volantis, Ellie's group scavenges winter gear to help travel, but because there wasn't enough for all of them, one member elects to stay behind. It's also entirely possible that they deliberately contaminated the food supplies with their own tissue - judging by the wall messages saying "eat of us". It is heavily implied that the people in charge of the supply depots deliberately sabotaged their own food, and that others susceptible to the Markers were compelled to eat necromorph flesh. Eventually, they all died (for a given definition of " dead"), and became the Feeders. Turns out, Necromorphic flesh is edible, but it tended to drive its eaters insane over the course of weeks. Now that the game is out, it's the "desperation" explanation. Meaning that it drives people insane enough to turn themselves into Necromorphs. If a Necromorph is killed, the Marker has a back-up plan. Makes sense, especially for Tau Volantis. People who are driven insane by the marker will stab their friends to write on the walls in their blood, so it's not too much of a leap to think the behavior induced could be ripping off necro-flesh and shoving it in their mouths. They probably did cook it thoroughly, boil it for hours, and soaked it in all the antibiotics they could find, but it wouldn't have been enough. Once you've gone for nearly two weeks without anything, it was either the flesh of their enemies or their own limbs. Either that or it's a weird Unitologist ritual. Once the food ran out a bunch of starving saps probably started eating some of the necrotic tissue growing everywhere.
On Tau Volantis the weather is cold and harsh, so it's unlikely there's much to eat there.Just what kind of event made people hungry enough to eat Necromorph tissue?.