Do you still have the guy?

No they dont need heat. They actually like it a bit cooler. they also like a substrate they can dig in, I use this block of stuff that I add water to. I feed mine red wigglers, earth worms and crickets. I do dust them with calcium powder every couple of feedings to make sure they are getting enough. When they are kept in captivity calcium deficiency is a problem. They dont need special lighting either, just ambient light.

I hope you will find a nice safe spot to release him come spring.