Mine are 8 weeks old and it's just been in the low 90s this week for the first time and they were panting a little bit... I think we're all just acclimating to the heat- I thought I was melting too! As long as they have some shade in their run I wouldn't worry about them not being in the coop- mine go in and out at will but my coop is pretty roomy, however they can catch more of a breeze outside.