Regarding the "Why does my Russian tortoise stay buried?" thread, I'm still mastering the combination of light duration, intensity, and temperature for my little dude. So now I'm wondering if maybe the ground/substrate of his tortoise table needs to be a little warmer (especially in the winter), since it sits off the floor. The lights seem to give off plenty of warmth (on a timer) but the substrate still feels a bit cool. I assume in the wild, the tortoise would derive some heat from the ground. Is there a good product that can help with this? Obviously I'm worried about the underside getting too hot since it's wood, so I was thinking of one of those heated basking rocks? (LLL Reptile's website was a bit tough to navigate for me.) Or maybe simply a space heater? Feedback welcome!!! 
Here is my enclosure if you'd like to look: http://www.tortoiseforum.org/threads/steves-new-enclosure-the-first-one-ive-built.80648/
Here is my enclosure if you'd like to look: http://www.tortoiseforum.org/threads/steves-new-enclosure-the-first-one-ive-built.80648/