I bring mine inside in the evening and take them back out in the morning. It is still hot here during the day and in the 70's at night. I have been doing this for about 5 days and I think they are already getting used to it. They would jump out of the box I used at first but now they get in...
We even put a small limb in it. They are 8 days old today. It's funny to watch them practice getting up there. Some of them take long naps up there now.
It is so much fun to watch the babies enjoy a dust bath. Mine were a few days old before we had their outside brooder box built and they loved it when we put them in it. We put it where they have access to a little bit of grass and sand to dust in.