HI this is my first winter with my chickens. The inside coop is nice and warm and at night (on the super cold nights) i put hot water bottles underneath the hay to warm up their feet. They are outside right now but it is -20 below with the windchill. Should i be worried? should i lock them inside? Will they go in on their own if they are too cold? I put vaseline on their combs, they have plenty of fresh water and food. Am I worrying too much? Thanks for any input!