I have 11 baby chicks I've had for 1 week now. They're about 9 days old. They have just started feathering on their wingtips. I keep them in a brooder in the garage because I have no brooder in my coop. I have a coop and 4 adult hens, 1 rooster. They're 7 years old. It's summertime here and daytime temps range from 75-90F during the day and about 55-70 at night. I can close the windows on the coop and put in a heat lamp if needed in the coop. Would they be ok in the coop ? It is sturdy and well built. I can put together a brooder section in the coop and add heat lamp. Just curious about temps being safe for them. If I shut the coop door at night and have heat lamp will they be ok at night?