Flexxwatt heat tape is pretty useful stuff, and when you cost it out, is pretty cheap, but you are probably going to have to order it online, shipping, etc. and you have to wire it yourself. They may sell it at home improvement & hardware stores up there, as it is one of the things used to heat floors, pipes, etc... But I've would think you would probably have to buy a whole roll, I'm really not sure.
I know you said you don't live in a large town, but you said you had a petco? I would get one of these. or you can get one at petsmart, etc... It'll probably be cheaper than buying two digital therms at lowes. And you can use it anywhere.
Yes you can bathe them, just make sure its not too deep, and not too hot, baby bath warm. The"sneezing" nose is most likely a little grunt like nose they can make when irritated. I would try bathing them, just be careful. If he does have parasites, he its probably dehydrated. That is probably part of why he is staying in the most hide.
You can also make it wet enough in there so there its condensation on the walls, he can lick those up too.
