I would probably go with either tetracycline, Kanacyn (or something like that, it starts with kana), or Maracyn AND maracyn 2.
As for keeping him warm, definately get a small heater. I would go ahead and isolate him and leave him in a warm area of your house if you don't have a heater or can't get one today. Where do you live? Right now I know my heaters only come on at night, and thats because I leave all the windows open.