I’m facing the same issue with my iPhone 12 Pro after updating to 14.2 and it enabled carrier update to enable 5G on Zain Kuwait. Whenever I’m on 5G, the phone tends to heat up and the battery drains a bit faster ! It cools down whenever I switch to LTE or connect to WiFi ! Ever since I had the phone (before 14.2) the phone operated smoothly with so issues of overheating! Could it be something with the update ? I had the same overheating issue with my iPhone 11 Pro after getting it just one week after release ! I have contacted Apple support and did all sorts of testing , resetting , re-installing from backup to no avail ! Only after iOS update that the phone got operating cooler ! Seems it’s either an iOS issue that can be fixed with a software update! 🙏🏼