How does everyone manage this? Our chickens have survived the cold without frostbite in the past, but I want them to be comfortable. I've seen mixed information on insulation or using a heat source, like an electric pad. However, I've seen reviews of even the safest heating sources causing fires. That would be terrible, so I want to make sure we are being as safe as possible. What do you do? We're in SW Virginia, so it doesn't get to negative temps or anything, but it still gets cold for birds!