I haven't found anything related to this in online searches, so i thought i would ask Lightroom users.
I have Lightroom mobile installed on my iPhone 7 and when i use it, the phone gets very hot. If the ambient temp is 90 or better (which happens quite often here in Florida), the phone will overheat and shut down after a while. I used it without that happening yesterday (ambient temps around 75), but the phone was still quite hot. I have a pretty thin Spigen case on the phone, and it doesn't get hot with anything other apps.