I have 7 chicks, 5 are in there sixth week and two are hitting the 6th week. I live in Utah and the temps will be right about 60 for the highs and the lows around 40 to mid 40. I have been aclimating them for about a week during the day and brining them in at night. They do look to be fully feathered so was doing some reading on when to leave them out and what they can take. I have read conflicting articles all over Google. Some say good to go at six weeks down into the 30s and others say 8 weeks so a little confused as to when to allow them to stay out 100% of the time. Here is a pick of what I have setup just for a little additional warmth and a couple of the group to show the feathering. FYI, I tested the heat lamp to ensure combustion would not happen.