You have 2 options, broadly speaking.
1. let them work it out. Maybe add more separation time and see if people chill out before combining them.
2. Keep 'em separated.
My experience over the last 45 years is that once we hit about 108 to 110, the ground surface pushes so much heat out that only the strongest storms can push in. Otherwise they just slide along the edges of the heat islands and stay out in the desert. I'm hopeful but not expecting anything in...
Yeah, they will slow down on feed when it's super hot. I also don't feed scratch in hot months. My rationale is that the corn is harder to process, requiring more energy to digest, which means more heat generated. Is it a lot? No, probably miniscule all things considered, but when it's over 105...
:welcome
You SHOULD be just fine with them introducing them as you have before. We had a couple frizzles and sizzles and the big kids didn't bother them after everyone figured out their places in the order. There are always exceptions of course, but with them cohabitating separately you will...
:welcome
Hello from the Valley. We have a pair of mini pigs and chickens too (a juliana and a "juliana" (some kind of mix). Drop by and say hi in the AZ state thread.
https://www.backyardchickens.com/threads/arizona-chickens.31227/
Reminds me, I need to go down this weekend and get some...