I have 8 chicks (EEs, BRs, red stars, and buff orpingtons) who are 7 weeks old. They are crowded in their playpen, so we try to let them spend their days in the tractor and outdoor run. We have no electricity out there, so at night we've been bringing them back inside to their 6 square foot playpen. During the day, we've had temps in the 70s and 80s for a few weeks. With unseasonably low night temps this week and last (tonight is supposed to get down to 38 degrees, but most nights have been in the 40s), I'm wondering which is worse: overnighting in low temps outside or being crowded together inside all night?