Oh, we see you, /u/M_n_M13. You've got a brooder full of fluff and a heart full of hope, but the forecast is giving you the side-eye. High of 42, low of 23, Minnesota in spring is basically a weather-based prank. And now you're staring at an eight-week-old chick, fully feathered, and wondering if she's ready for the great outdoors or if she'll turn into a tiny, frozen statue overnight. We've been there. We still have nightmares about the wind chill.
Let's cut through the clucking confusion. Yes, fully feathered means your chicks *can* regulate their own body temperature better than a featherless ball of panic. But "can" doesn't mean "should" when the thermometer is flirting with freezing. Those feathers are good insulation, but they're not magic. A week and a half of lows in the 20s, with no older hens to huddle against, is a lot to ask from a bird who's only been alive for two months. We'd tell you the same thing we'd tell our own anxious self: hold the line.
Keep them in the garage with a heat plate for another couple weeks. That's not chickening out, that's being smart. The heat plate gives them a warm spot to retreat to without turning the whole garage into a sauna. Set it low, around 85 to 90 degrees at the plate surface, and let them decide how close they want to get. They'll tell you if they're cold by piling up under it, or if they're fine by wandering off to peck at their own reflection. Listen to them. They're better at this than we are.
Once that rough patch passes and the lows creep back into the 30s, then you move them. Give them the heat plate in the coop for the first few nights, just in case. They'll have time to figure out the roost, the drafts, and the existential dread of hearing a raccoon sniff at the door. By then, they'll be tough enough to handle Minnesota's next trick, probably a hailstorm in July. But for now? Garage, heat plate, patience. Your chicks will thank you by not turning into poultry popsicles.