Hi, I have 6 chicks at 4 weeks old and they look pretty feathered... just a little fuzz still on some heads and necks. I had them inside under a lamp to keep it at 80 recently. It's gotten ridiculous because I have to run the AC and the lamp to keep the temp constant yet its 80 outside right now. I just moved them out to a small coop inside my main coop and run so they are kept protected and away from the other birds for a while. Temps for the next 10 days say 80-90 during the day and 73-68 at night. It will be about 70 tonight and therefore cooler then they have experienced yet. I noticed they are all on the ground near each other sleeping since this is the first time the light has been off them. The mini coop / box (3' x 4' x 2') is closed up except for a crack at the top for air. No lamp. I am assuming they will be fine since it is not cold and since there will be no drafts and their own body heat will probably make it slightly warmer then the air at night. Can someone confirm my assumption? Do I have to open the lid and put the lamp on them again? It will be 70 in there and the lamp will make it 80. Thanks!