I know this is asked a lot, but since there are so many variables, I thought I would ask about my specific situation. I live in western PA and the average low is around 30 right now. I have ten 10-week old pullets and 6 that are 5 weeks old. They are all together in a brooder in my 50-55 degree basement and haven't had a heat lamp in about a week. They are too crowded and I want to put them in the coop (totally separate from my current flock). I put lots of hay in the coop and it's pretty close to draft-free. I am very comfortable with the older ones going out, but will the 5 week olds be ok? Should I put a light in the coop for a little extra warmth?