Hi. We just got 16 chicks and I'm going to be building a separate area in the coop to move them to when they get to big for the box their in right now. And I want to build a small, separate, completely fenced in, (including fencing in the top so nothing can get in) outside area for them. (it would be a 4x4 area) But my dad doesn't want to allow them to go outside until their big enough to be with the rest of the chickens, he's afraid that they will die and he will lose the money he paid for them. I live in Howell Michigan. So my question is. How old can chicks be before going outside in the day? I would make sure they are inside at night, and they will still have the heat lamp for the chilly nights.