[Xperia Z3 Q&A, Help & Troubleshooting] AlvinZahran98:
this just happened a few hours ago.

I've visited my grandma today in some places in Metro Jakarta Area, and boy Jakarta is as hot as the hell of the hell, when i go there, to her house, it actually looks green and cold, despite that afternoon it's sunny. but boy when i got out, it just burns my brain, head, and body inside and out.

So I kind of played some music in my car, but i turned off the music, and i got out of the car and go to the house, when i came in, wow, just wow, it's like i've just came in to hell, you know. Well in that time, i didn't feel that hot inside me, but my phone didn't feel the same as me...

you know, when i got out, i had my phone on aeroplane mode, and i don't do anything with my phone, after i came in, i just did light things with my z3, and after that, i played some games, and the phone started to became warm, well not that warm, but just a tad warm. and when i finished playing the game, i closed the game, and then lock my phone, and my phone seemed like it didn't like the environment and the air quality inside the house, so it became really really warm after that, i checked the temperature at cpuz and i saw the battery temperature, that is at 36 or so celsius, and i saw the thermal, most of them are like 40-50, and it is raising. and it just slowly getting hot until it is super super hot, i got panicked that i don't check the temperature and just turn off my phone to let it cool down.

Well my phone is new, and here, people are just ambitious when some person got a new phone, especially when it is a good one, like s6,z3+,iphone 6, or something else, especially z3 like mine, because sony users here are a lot but i rarely seen the users. so when i turn my phone off, my uncle was looking at my phone and started to tell me that he want to borrow it for a minute, so i gave it to him, i forgot to tell him that i turned off the phone because it experienced overheating that time, so i think he turned on the phone, i saw that fancy startup screen with that purple flow thingy, so i told him late, and asked some questions about the phone, and then i took the phone. I got panicked again because it's getting even hotter.

well that room is super super hot you know, but i'm one of the people who hate hot or warm environments, but i don't feel that hot, although it is warm, but some people thought that, that room is as hot as hell. so when i checked the phone, i saw that the startup screen is still running, it's unusual because it should display the lockscreen that time, so soon after that, the phone got lagged startup, and a few seconds later it got freezed, and then, like 5-8 seconds after that, the screen is pitch black, i thought the phone died, but it was restarting again, so i wait a couple of seconds, and it just did the same thing as before, so i'm worried, after like 5 times of doing the same thing, i asked my sister if i need a pin for force reset the phone with the button inside the microsd/sim slot. And then the screen turned off with 3 times vibrate, that was my first overheating and my first time of reseting a phone like that on my z3,

Oh yes i just remember, the phone is at 13% that time before the first turn off. And continuing on, when it already cooled down, i pressed the power button to turn on the phone, and again, that thing happened again, and it overheats again, i got really worried, so i let it cool down again, and then i tried to turn it on again, but did the same thing, so i turned off the phone again with the same method, and take my charger inside my car, and charge my phone, after that, it charges at 9% mark, i let it charge for some minutes and then, i turn on the phone again and just pray :D , then finally, the phone turned on without an issue, when i tested everything inside and outside it, everything seems normal.

that is creepy you all know? hahaha :D

btw, i'm not really in jakarta, i'm in sawangan, depok, it's like jakarta's sub city/ inside Jakarta metro area. but both are as hot as hell.

edit : oh yes, it's not just me, my mom's gnote 8, my sister's iphone 5s, and even my blackberry curve 8520 did the same. but my z3 is like, far severe one

but other than that, my phone didn't feel and seem as bad as you are, i just got like warm but not that much heat on mine when trying the same thing with the same condition as you are.