I have about 80 Cornish cross chicks they will be 3 wks old this coming wed. I have them in an outside shed with heat lamp now, with plenty of room for them to get away from the heat if they need to. It's going to be cool this week, lows in the mid 40's tonight and tomorrow, then moving into the mid 50's by the end of the week (for lows, highs mid 70's). At what tempts/age will it be safe to move them outside. I've read a couple threads on here, and the answers range from "too cool, warm enough, not to cold" does anyone have actual tempts to go by?