If this helps....I purchased 7 chicks that consisted of 3 who were a month old and 4 who were a week old on the date of purchase. The first week they were all inside but when I got home from work I would take them outside to a little run for a few hours for some outside time. One night it seemed so warm I decided to see how they would do spending the night in the coop. Next morning they bounced out happy as could be. So the next night, I put them back in the coop. Skip forward a few days and we had a cold spell. This was about their 4th or 5th night outside (at this point the older ones were 5-6 weeks old and the younger ones about 2 weeks old). Around 11pm I noticed on our satellite thermometer that the temp had gone below 60 degrees. I was concerned about them and decided I'd better at least bring in the the four little ones. So out I went in the dark with my cat carrier and a flashlight. I found three little ones and put them in the carrier, but couldn't find the fourth. Eventually I turned on the flashlight and discovered that the fourth was sleeping under the wing of one of the 5-week-olds (just like it was its mother!). I pulled it out but it was warm as toast. At that point I realized they were all doing just fine, put the 3 back in, closed the coop door and went back to bed. We had several days in a row that reached unseasonably low temps at night and all 7 of them thrived throughout.
