I have 12 chickens, 6 Red Sex Links and 6 Barred Rocks. They are now 6 months old. Tonight it is supposed to get to freezing temperatures. Are we supposed to put a heater in the coop? A heat lamp? Anything? The coop is well ventilated and we can close the door at night. They have not layed eggs in days, which I thought it is weird, is it because they are too cold? Please help!