No offense, but why would you put him back out in a snow storm if he looked like he wanted to stay in the warmth, and he's sick? I don't understand that part. It just seems cruel to kick him back out. Do you have a spare room to shelter him?

Try your local Walmart for material that's like a sheepskin/sherpa like feel, and you can put that inside the carrier, to line it. Then you can put the carrier in a large box to buffet it from the wind. At least that way he has some shelter.