My issue was I was filming in 4k 30 in Florida. It was about 90F out. About 15 minutes in the screen dimmed so bad it was almost black and I got a warning that the phone needed to cool down. I have filmed like this DOZENS of times with my 14 pro Max and yes it dimmed but you could still see the screen. Plus I never got a cool down warning. This wasn’t even a really hot day. I did have the 15 pro max in a case, but my 14 was in a case too. It is worse from a filming standpoint thermal wise, at least for me.
Today I had my phone get up to 100° doing nothing other than use an App that doesn’t even do anything other than view jobs.
I barely used my phone for the day and my battery was at 60% at 4 PM. I have never had that happen with my iPhone 14 Pro Max.
I called Apple and did a service call. They ran a diagnostic asked me a bunch of questions and of course said everything looked like it was fine. I have an appointment to go to the Apple Store on Monday of the coming week for them to look at it to see if maybe mine has an issue and I can get it swapped out on Warranty.