Thanks for all the fast replies. The person I picked him up from used the heat rock for the 4-5 years he has had him for. I have read on multiple sites that it's not good while reading up on them this morning. I will be on the way to the pet store but wanted to research a bit first. Currently he is on a sort of felt. Before the previous owner was using the "astro turf" but didn't have any left to change out. I have seen any sites recommending sand (I was thinking the digestible type) so was looking more into wood possibly cedar?

aspen or reptibark. newspaper is real easy to clean
Looks like newspaper it will be. I know that the humidity is fairly low around here during the winter.