When you first get chickens do i keep them locked up in my
shed for a couple of days so they all get used to each other before letting them out
cheers Phil
What age? If they came from the same flock they already know each other. They do need to get to know their new coop. Keeping them locked in the coop for a few days to a week will reset their idea of what is home.
beware of shutting them up in extreme heat. If the run is attached to the coop, so that is the only two places they can go, I would not shut them up during the day time, even if I did have to put them in the coop at night.
Confine and ventilate. You have two killing options here. First is by over heating. Second is by them not adopting safe roosting location and being taken by predators.