I have an automatic pop door - really nice one - its been perfect right up until it got cold. Darn thing wont open for anything unless I use my propane heater to heat it up (from the outside of the coop). Plus - the large door I enter the coop from is so cold it has shrunk & is messing up the allignment of the henges. So the bottom of the door kicks out & is a bear to get closed! Poor chickens have been stuck inside for 2 days playing teather ball with a cabbage. Thats all not to mention the eggs popping like popcorn. I sure am tempted to heat the coop - but there is just too much moisture in there to do that. I hear that Monday is going to be the worst so far. Down to Zero Ferenheight with a wind chill of - 15!!