I put in a fairly low wattage heat cord - 50W ($30). I have an 80W in reserve, but haven't needed it. The warm spot is above the cord on the basking (VCR/DVD) shelf where I get nice 32 degree readings. That is where I have my thermostat probe. The branch below is lucky to hit 25 during the day at the moment because it's very cold in that room. I've found that in enclosures where my Darwins have a choice of a shelf or a branch, the adults generally opt for the shelf, so now I design accordingly and make that the basking spot. Ra hasn't used his hide box at all. He seems to feel quite secure on the shelf with its low ceiling. When I put the female in with him, they both opted for that spot most of the time. Haven't caught them in the act yet, but I'm hoping that it has happened. They had a week together, so now I'm giving them a few days apart.