Chosen Solution
My iPhone 6s is draining the battery extremely fast and is heating up just below the rear camera. The phone operates for about 5-10 minutes then gives the overheating warning. I have tried a new battery and the problem still persists
You need to start disconnecting components until you’ve figured out what is causing this issue. An easy way to do this is to simply put the screen at max brightness and set the Auto-Lock to Never. Start by testing the telephone as-is to set a benchmark . A normal should deplete ~4.5 hours, depending on the condition of the battery. Then disconnect the Rear Camera and do the same test. Then do it again with the Front Camera removed etc. until you figure out which part is causing the rapid battery drain. Always remember to disconnect the battery prior to disassembling or re-assembling the innards.
