I'm in Michigan and we're getting temps in the teens. My girls have a 4x3 space for nighttime and i have a infrared lamp that goes on at 5am so they get their 16 hours of daylight, but I have it turned off a few hours before they go to roost. There is plastic around the whole coop and a bit of foam board insulation above and below their roosting space. It's been sooo cold at night, I'm wondering if I need to do anything else for them. My "chicken guru" who set me up with the chicks says they can take temps to 0 degrees F. Is that so? I'm new and learning and appreciate any feedback. I did look at other posts (cold in FL) and read those, but I'm wondering if I should keep the lamp on all night - will that interrupt their sleep? I also thought of an portable heater.....Brrrrr.