Changing his temperature might not be a good idea. Plus it might stress him out if you move him around. It's not too cold out at the moment, I would leave him outside but cover his hutch (if he has one) with a rug or fleece.
And if the baytril doesn't help I also recommend penicillin. I've used depocillin with great results but some vets don't really know about it. It has to be injected, usually every few days for a few weeks. I got taught how to do mine and did it at home.