I'm gonna have to think on that one. I used to start out at a temp that seemed comfortable for them. So they weren't piled ontop of each other but not scattered far away from the light. I guess they would lie kind of in a circular spot under the light and I just learned from watching and listening to them that they were comfy and then I'd lower the temp by about 5 degrees a week. I would put up a small cardboard ring around them in the coop to keep them closer to the light and gradually make it larger so they'd have more room. When they're big enough to fly over the ring that was about 2 ft tall I gave up and would take it down. Make sure you sprinkle their feed with chick grit so they get somebody that in their diet and until they're a few weeks old you'll have to make sure they're buts don't get pasted shut with poop. If they do you'll have to soak it with some water and gently remove it. If you have any more questions ask away. Ill be glad to help.