I have my first batch of meat birds. Right now they are in my largest brooder box in the garage with a heat pad and a brooder heat plate, but they are rapidly outgrowing it. Since it's fall I'm not sure when to put them out. Our day temps will be in the lower 70s but dipping to low 50s at night. Can they be out at night if I put the heat sources in the sleeping area of their chicken tractor? Thanks!