On the warm side, I have my lamp with a 50 watt bulb and a UTH on the bottom, on the other side I've got a little log hiding place and a plant. The top is just a regular metal screen top that I've put a towel over half of to try to trap some heat inside. Since putting the towel on the top the temp has gone from 70 to 75-78 degrees, which is an improvement but maybe I'll try tinfoil out.