Put them in the coop. Wait until dusk, or the moment they go to roost on the railing if you can and put them on the roost bar.
The cold isn't the problem. The mesh outside is. That mesh won't stop a weasel, or a mink and I can't see in the picture any protection from aerial predators.
The cold isn't the problem. The mesh outside is. That mesh won't stop a weasel, or a mink and I can't see in the picture any protection from aerial predators.