Odd behaviors

Hey, guys. Weird things are afoot.

We fed our chickens a normal meal of lay crumbles at about 4:30pm local time (Los Lunas, NM, where the temp today reached about 90°F with mild/moderate humidity). They seemed agitated when we fed them, but we didn't notice anything very unusual. Around 8pm, we heard a kerfuffle out in the coop and went out to notice that all our birds were on top of their nesting boxes, food on the ground untouched. Haven't even touched the apple chunks or meal worms we'd given them as a treat today, which is very unusual for them. When I put the apples up top where they were standing on the boxes, they ate them like crazy.

Possibly related to this behavior, both of our roosters' combs are turning purple toward the backs of their heads.
Our buff rooster gets frostbite easily in the winter, but it's been getting down to a low of about 50°F at night and the barred rock rooster also has the purple comb tonight and never gets frostbite.

Any ideas? We presume stress, but didn't see any evidence of anything other than a few ants and a scurrying mouse... their water is clean, flowing easily from the poultry nipples, and freshly changed out yesterday.

Behavior like that can indicate a sudden stress. Probably another big bird that came down and scared them or one of them might have seen the 'boogie man' and when one chicken tends to 'see' something, they all do.
A colored comb could mean a variety of things. Circulation, disease, frostbite as you said...it could be various things. Chickens aren't like turkeys where a change in mood or body temp can cause a color change in comb, so I would look at other options.

Something disturbed them when you heard the racket. Go check again with flash light making a quick scan around coop as you approach. Get birds up and roosting on something in center of pen.

If what I have experience with it will be back and possibly never left area when you first came out.

Thanks, guys. They were all back down on the ground like normal this morning after their brains "reset" during sleep. I was hoping the stress could have been the cause of the purple combs, too...especially since both our boys have it. I hope they haven't caught something. We'll keep an eye on them. :/