Pulse was low at about 120, what you would expect from Anesthesia. Cat was quiet, but minimally responsive, even to the point of managing to purr. Doctor put him under my care at about 8:30 AM.
I gave him a heating pad, a hot water bottle and blankets. I got a minimal response of about a half degree per half hour until about noon, when his temperature went up about four degrees. It kept gaining slowly until I left at 7PM, when it was 98.5, Still below normal, but out of danger.
As far as I can tell, ALL of that body heat came from the heating pad & bottle, and this cat is not generating any body heat of his own at all. My RVT school didn't cover anything like this. We covered in detail what causes a fever and how to deal with it, but I have no clue what would cause this.
Outside of being lethargic and having a body temperature of 89.5, this was a completely normal looking 8 year old DSH neutered male cat. They didn't do blood work as I honestly do not think they thought he was going to survive the day. I also think this may be a charity case.