I bought a female baby ball last week from a very reputable reptile store. I was told that all I needed to heat the tank is a heating pad, so I bought that. After a few days, I wondered why my snake never hung out on the side of the tank where the pad was underneath. I felt the glass and it was burning hot. I picked up my snake and she was ice cold! After a call to the store, new heating pad, and finally lifting the tank up on pieces of cardboard, the glass seemed to be an acceptable heat. However, my snake still doesn't like going on that side of the tank and she feels rather cool to the touch.
Should I be worried? Does a healthy snake feel cold, warm, or hot? I feel really silly in not knowing this but I've never had a reptile before so I have no prior experience to go on. Thanks to anyone who can help me out.

