While I was at work my heater shut off. I got home and checked on spike and his belly was cold, he wouldn't unball and he's wabbley now. I got him to unball and I warmed him up. he's on a heating pad now. It's been about 5 minutes. What else should I do and how long do I keep him on the pad. I know he needs to be watched because he may attempt it again but what do I need to do now?