I use a 40 watt CHE Nano. It's fine. He has laid on it before and it still only tops out at 85F. It's more the ambient in the cage. Plus, like i said, i only use a 40 watt nano CHE which are the tiny ones about 2 inches in diameter if that, so he has plenty of space to get away from the heat if he wants. He actually spends most of his time sleeping on a perch behind his plant on the other side or actually on top of the plant itself. He only comes over to the warm side after he eats.