We live in Southern California, but when we got our chicks in mid-June it was still in the 60's at night and not much better during the day. We keep them in a 5'x2'x12" long box, but at about 4 weeks they started flying out of the box even after I'd built up the sides to 24". We had out coop and run already, so we just moved them out with the 250 watt red lamp and never looked back! They are so happy and have grown even bigger and faster. They love it outside. I know all the books recommend keeping them in for 6 weeks, but I don't know how you'd accomplish that in a house. They say no garages, etc., where heat can't be contained. So the coop was the best bet. We also covered the nesting box hinge ares with a blanket and another one on the gate inside the doors to keep out the cold.