Can I leave the pop door open during the winter? I have a double walled chicken house (6 x 8 ft) with a pop door to allow my ladies and gentleman access to their enclosed chick run (10 x10 ft heavy duty dog covered dog kennel). They also have a 50 x 50 ft chicken yard to play in during the day. My question is, can I leave the pop door open this winter or do I need to build a wind block or something around it on the outside. I have screened windows which I have left open all summer until it got down to 30 degrees at night. (28 last night!) I have 11 young hens 19 to 28 weeks and one 20 week old rooster. When people talk about ventilation, how much are they talking about? I also have 2 small barn windows that I could open. I am just not sure about these things so please give me some help. I also bought a heating pad for under my waterer. Can I leave it outside all winter? As you can see, lol, I have lots of questions! Thanks in advance for your help.