Our Cornish Cross chickens are 3 1/2 weeks old and have been brought out to the A-frame tractor to forage and get used to their coop during nice days and brought back in at night and in any cold weather. Temps here in TN are unusually cold this winter and temps for the next 2 weeks are forecasted to be highs in the 40's and lows in the mid-20's. Does anyone out there have any experience raising this type of chicken in this cold weather? We really hate to watch them spend their short life in a box in the garage when they should be outdoors where they can move and be happy. Any advice on heat sources/lamps in the coop? Thanks in advance!