Okay, our coop is 8 feet long, 4 feet high, and 4 feet wide. So, we can't really fit a very big heater in there. We put thick plastic sheeting around the sides and top of the coop, and bought a small personal heater fan that we plan to hang up inside the coop, up high towards the center on the back wall. We also are keeping the straw bedding thicker. Is there anything else we should be doing, or something we should be doing instead of something we already are? Thanks (total of 3 chickens)