I have 6 young silkies (ranging in age from 7-8 weeks). They have been in the house (temps 64-68) until today. I took them out to their new pen and they have been happily poking about all day. Temps today were in the mid 40s. Temps tonight are supposed to drop down to 25 degrees. Daytime high tomorrow is 39, with nighttime lows in the mid 20s again. The coop is a 2'x3'x30" box made of 3/4" plywood. There is no insulation and it sits on the ground. It has 2-3" of shavings in it. There is no heat lamp and no electricity near the coop. The 6 babies will be the only ones in this coop. The question- Should I bring them back in the house tonight and back out tomorrow and so forth? Nighttime temps aren't really going to improve for a few months. Will it just mess up their systems to go from cold to hot to cold? I had planned on putting three milk jugs filled with hot water in the coop to work as a heat sink. DO we think this will keep them warm enough? I don't want little chicken popsicles. The other outside chickens are fine, but they've had time to get acclimated.