I'm new to raising chickens, and this will be my first winter with them! I have 11 chickens. When I got them they came with a 4'x10'x8' "coop", which was basically 2x4s screwed together to make the frame and chicken wire for the walls. I added plywood to make walls (darker, feels more safe, protects from wind, extreme heat - miraculously got eggs for the first time within days of doing that), except no plywood on the door, which is still framed chicken wire, basically like a screen. The "coop" is up against the wall but there's about 6" on one side that is exposed too, also chicken wire. That is inside of a larger run, fenced off chicken wire about 200 sq ft or so? I live in Poway, CA, where the average lows in the winter are 40s, but can get down to the 30s. I'm sure that on rare occasions it gets to the 20s but haven't experienced that, and it definitely NEVER snows here. So, my question is if I should get a heater, and if so, what should be my guidelines for when to use it? I know tons of people out here have chickens (because I can hear the roosters) but I have no idea what they do in the winter or if it would be silly to get one? Oh, I'm not a crazy chicken lady but I don't want them to die of frost either. Please help!!