No reason to panic yet, it could be from dehydration. Have they been drinking enough water? How hot was it? Do they have a shady place to hang out? Chickens are better in the cold, rather the heat.
If yes, you could buy special comb and wattle treatments, to help hydrate them.
I've had chickens before, once one of my hens went broody and we gave her at least 24 fertile eggs, (12 at a time), and none hatched. :( So I am looking to hatch eggs, because it's always been my dream. I am looking for quail or chicken eggs, or maybe another small bird that's available. But I...