Definitely a vet visit in order (do transport with heat packs). You can find the shake type instant heat packs in any sports department, hunters use them quite a lot. It's always good to have some in the house for emergencies like this. Do remember to make sure that your snake can't directly lie on them or swallow them though.

I will try to find the link I had before my computer died a few months back. It was an alarm that plugged into your wall socket, then you could plug your tstat into it. If the power failed on that outlet a very loud tone goes off. It retailed for about $35.00 and was for medical equipment if I remember correctly (Christie if you still have the link could you post it please). That would certainly be helpful if the power goes off while you are sleeping and you don't notice it all snuggled in your blankets.