It's because the Cold Blooded modifier completely ditches vanilla hypothermia in favor of hypothermic slowdown. Which is fine until you realize that this change makes it so they *can't lose hypothermia if they somehow get it*. Even if they're sitting in rooms at 100 degrees Celsius, they don't warm back up.

Hell, some other Vanilla Expanded series mods have things that apply hypothermia to pawns (ie Psycasts frost psycast tree and Vikings cryo weapons), which in turn can't wear off because it's not hypothermic slowdown. How the hell that got past bug testing and QA is beyond me. I even brought it up back in what, November? and got ignored.