I don't have a thermometer in the brooder because I was just watching their behavior to determine if the heat lamp was too close or too far. The brooder is in our spare bath tub in our house, so it's always fairly warm in there anyway (68-70 degrees). We have the heat lamp pretty high and they still don't hang out under it. Our BOs are 3.5 weeks and the LBs are 2 weeks. It seems early to remove the lamp but I'm just wondering if they're in the house, maybe it's warm enough without it?