If you’ve had them in the coop for several days they should be “homed” to it and will go back in at night on their own (as long as there isn’t a more tempting place to sleep outside, think high perch or low tree limb).I have yet to let my littles, almost 3 weeks old, into the run. It is fully covered, and has a large fan blowing into it, but so far, I am keeping the temps just under outside temps with all I mentioned, plus, now I have a gallon jug of water that is frozen, in front of the fan I placed just outside the run door. The fan blows onto the bottle as it thaws, cooling the air down in that immediate area. The babies tend to gather around it staying cool, and drinking the cold water condensation on the outside of the bottle. It is like the office water cooler! lol
Plus, I am not sure I would be able to get them back into the coop at night. I am going to need to rehome some of the babies, so hopefully, when I get the numbers down to what I can keep, I can get them in and out easier.