Don't give up! They can survive not eating for a looong time and being cooler won't kill him right away. Did you look at the link for the bottle trap that keeps him inside it once he's in? Also once you've checked a room completely and you're sure he's not in there wedge rolled up dish towels or something similar under the closed door cracks so you know he's not moving between rooms you've already been through. Something else that might work is hanging a heat lamp above a hide on the floor of a room. Nice warm place for him to stay put for a bit hopefully....I've heard of a number of snakes that have been lost for a week or more and turn up eventually Good luck!! I'm hoping for ya!