I've noticed my iPhone get hot the most while using the camera. Especially while taking video, but after a few photos it gets hot as well. I was on vacations last week in a tropical country and took a lot of photos with my 16 Pro and it gets so hot after just a few photos that it starts lagging A LOT due to the throttling.

I'm sure this is handy for LLM usage, but this was a problem before those were a thing I'd say.

I have the same case, iPhone 16 pro is getting really hot when taking photos and videos it’s unbearable. I will change my phone for that reason, the battery melts right away … I noticed something though, when taking a picture with the x5 camera if I cover the main lens the brightness changes. So I think the iPhone now merges the two stream to enhance quality. That wasn’t the case before and that might be why the phone is getting hot

My 16 pro is frustratingly laggy taking photos all the time, particularly from the lock screen. It's a little better from the camera app.