I have 8 of these racks. I love them. They all have belly heat. I have a tempeture controlled room for the snakes, The ambient temp stays at 83. I use the common 40 watt flex with helix therms..I usually get 83 on the cool side and 92 on the warm side....I wouldn't let the room get that cold in the winter unless you rig up some additional flex for the cool side and run it on another helix...or you can get an oil filled space heater and heat the room up a bit...