ok, that was on the cold side.LOL sorry about not being specific. the hot side is around 92-93, and I do use a rheostat ( I do not have the money right now to buy a thermostat) It does seem to be doing its job right. I use thermometers with probes, One is on the top layer of the substrate, and one is Buried to where it reads the Hottest point the snake can get to..on the UTH. any other questions or answers