I adopted an 8 month old broody BSL hen. She adopted and hatched 4 RIR 3 1/2 weeks ago. The guy I got her from said just stick them in the coop and she would do the rest. I keep hearing never put a heat lamp in the coop. I have a 4'x4' converted dog house. It has openings in the peak on front and back. The weather in MI had been nasty since I got them on Tuesday. This morning the water had a layer of ice. There is pine and straw in the bottom and they haven't been outside yet since it's been so cold and wet (last night it snowed). Am I just a nervous new chicken owner or should I be concerned about it being so cold? The babies are 3 1/2 weeks old and mostly feathered (I think). I gave fresh warm water and warm oatmeal, applesause, dead mealworm, and fine grit mix this morning along with chick grow crumbles.Thanks for any advice!