I've read through a few existing threads, but I felt compelled to ask my questions... I'm in Southern NH, and we've had some cold temps over the last few nights. tonight it's going down to -20. We have a plywood coop. We have 2 vents near the top of the roof. 3 birds on a round pole roost. We just shut off our water heater because the humidity started to climb inside the coop. Should I be worried? Should we add some sort of heat or just let it be. The temp outside is 2 degrees, and the temp inside the coop is 7. It's just frigid, plain and simple. Any thoughts? Thanks in advance for your advice.