Thanks. My big problem is due to culling because of illness in my rescued battery hens after I had already brought in what I thought put my coop to max with spring chicks and two Aussie "hens" I bought turning out to be two roos, I've wound up with fewer birds than I should have for the size of my coop and all the adults are still molting so bad that when I open the coop in the morning it looks like they've been in a pillow fight! All were doing well (except my one Leghorn "mutt" because of her molt) with no heat till this cold hit today.Heater works. Plus you save on feed. I just whack the corn to my birds and they do fine too. Plus there is 11 birds all total. They bunch together and share body heat to combat the cold. Either way you must fuel the birds to keep their body temperature constant. Whether it be through nutrition or supplemental heat. My birds have went through -40º C&F. You birds may not be as cold hearty as mine. Anytime it snows in my area the temperatures are not as cold never double digit frigid. What ever gives you peace of mind.