Reviving my phone after a small part of it (eg the processor) overheated I tried to compress my 1.6GB video in the Media Converter app by exporting it to mp4(h264,aac) on my OnePlus 3 as per https://www.quora.com/How-do-I-reduce-video-size-on-Android. However, approximately 75% of the way through the conversion (after about 30 minutes) my phone overheated and turned off (with the screen going black immediately and no shut-down procedure). I tried to turn it on in the normal way, but it would not turn on. After leaving it to cool for 5 minutes, I plugged it back into the charger and it immediately turned on automatically (displaying battery at 30%).
I tried to compress the video a second time, this time putting my phone on an ice-pack to keep it cool and leaving it on charge. I touched and checked the front and back of the phone regularly to ensure it was remaining dry, was not cooling too much because of the ice pack, and was not overheating (it remained at something like 20 degrees C, approximately the same as the top of the ice pack, through most of the process - although the bottom of the ice pack remained cold). This time it turned off after 45 minutes, 1 minute before the conversion was due to complete. Immediately after it turned off I noticed a very small area near the speaker (I assume near the processor) was overly warm (though not hot). I assume the heat could not escape fast enough from the hot processor into the body of the phone. Maybe the internal thermometer was closer to the ice-pack than the processor and 'tricked' into thinking the processor was cool. Now my phone is not turning on, displaying anything on the screen, or vibrating, even after plugging it into the charger and unplugging it many times over the past 12 hours. What can I do to try and revive my phone?
I managed to turn my phone on by myself. Hopefully it will continue working.
I warmed up 2 plates in the oven to 80 Degrees C, took them out, and put a third (cool) plate with the phone on top of them. Once they had cooled enough to hold my finger on them, I stacked them into a warm plate-phone-warm plate sandwich, with the top plate upsides down. This warmed the phone up quite a lot, and was meant to allow any moisture to escape. Maybe it also affected the battery. In any case it turned on after 30 minutes of warming.
I would have put my phone on the radiator, but the weather is too warm to turn the radiator on right now.