One last post on this and I'll let it go. Last night, I had choir practice and so was gone from 6 PM to after 9 PM. We were high in the upper 80's yesterday and lows last night were to be mid-70's so I decided to unplug the heat lamp. This meant absolutely NO light once it got dark. I figured if they didn't make it into the coop, they would survive outside if they so chose. Of course, the first thing I did when I got home was to go out and see where they were. Using a flashlight (it's REALLY dark here with no ambient city lights), I viewed into the pen and saw no chickens. I kind of shined the light in the doorway of the coop and sure enough, there they all were. So, we have now fully crossed this bridge. They will be 8 weeks old next week and at this point seem to be feathered out enough to survive most anything weather-wise. Thanks, again, everyone!!