I just got my chicks and was very worried about having exactly the right temp. I put a little thermometer in there and then put my heat light on top. The thermometer was reading 85 degrees and the chicks were happy and playing. I decided that was probably too cold, based on the thermomer, so I put a red heat lamp on it to raise the temp and the next time I looked in on them they were piled over on the cold side trying to get away from the heat. So, I've tossed the thermometer, raised the heat lamp and take all my cues from the chicks!