I have 5 and 6 week old chicks. There are getting way to big for my tub in the basement. I have a large plywood box that they could move freely in and we built a roost. I know it is too cold and they are too young yet to go into the coop. I was wondering if I could move them into the garage if I still keep a heat lamp on them. The lid that would cover is half plywood and then just grates on the other half for ventilation. It is in the 30's at night but warmer during the day. Like maybe mid to high 40's. They seem fully feathered except for a few pieces around their head. I think the exercise would be good but I just don't want to cause health problems for them.