[Oppo Find 7 and 7a] opposeeker:
It's mid of September, but the weather is fine. The sun is shining. It's 33°C which is unusual for this time of the year.

Overheated birds are falling from the trees - they are not used to it.

I am sitting here in front of my screen while asking myself:

WHY do some people have overheated and very stressed devices....and other's don't?

Due to outside temperatures....??? :confused:

There may be as many answers as people using their phones. Probably.

Even when our highly honorable [MENTION=911982]Injected[/MENTION], being the GRILLMASTER of this thread ;) was talking about his 75°C, there were others having no heating problems at all - same device, same build (incl., but not limited to myself). At least we were informed by him, that he was gaming like hell...so that may be one reason. If you use your device heavily, it may get warm or even hot...that's a physical phenomenia ...that's the way it is.

However, what can I do about it...?

Simply and straight: N O T H I N G.

The sources come from RR, Google, CM, AOSP and last but not least Qualcomm.

Minor changes made by me (i.e. LVM injection (see long story in OP) and just recently I re-converted a change in the sources to re-enable the offline-gestures again) don't reflect the heating/energy issue. Kernel is original CM. All these sources are freshly pulled for breakfast before they are going to be compiled by me and served for brunch to you. If there were a general misbehaviour with overheating and/or an excessive energy consuming issue, we would read about it in high numbers. Not only here.

Watch the RR community thread. And get involved there, too.

So, back to the original question: Why....?

Here are some insights, just smashed out the (overheated) brain -> watch as an incomplete destination board:

Fresh install, OK? For me, yes. For you...? But...how do you get back to your installed apps? What apps do you have - and what do they do in background? What do you do for energy saving and how do you protect yourself (resp. your apps) from calling home all the time? What about GPS...Bluetooth (on all time or just turned on when needed)? What about sceen density and level (adaptive brightness or full brightness all the time)? Light or dark theme? Did you find about about each and every other setting other ROMs may not have? What cable are you using? Do you fully charge? And so on. These issues are general, but become more important using a ROM like RR which comes with many more features (and apps) prebuilt which you otherwise would have to install manually and therefore may be more aware of it, if you'd install them on your own. You could disable apps you would not need but don't want to (or cannot) uninstall. You could check i.e. secret settings in the prebuild dialer app, which is usually setup in checking dictionaries in the web for "your convenience" (just a sample). Does Google Store Service needs microphone access...? You could use i.e. Greenify to set bad programmed apps to sleep (latest version dd 12 Sep). To find out what the hell is giving you problems you could also use BetterBatteryStats and the pre-built Kernel Adiutor (see Settings -> Performance in RR). You could stay away from games which may not only eating your brain but giving you (battery) drain (haha). These are just samples animating to go thru (maybe hidden) settings of the ROM - in the summary it may help you to better manage your device and its features - including the unwanted ones ;)

May these hints be helpful...this is all I can do.....

PS: One more note - if you really think that something is going real wrong with your device due to this damned ROM you just flashed - and it MAY be something that could be solved here....why not asking the community. BUT please (try to...) THINK before you POST!

Postings like: "I have a hot device and my battery is nearly empty" I mean, seriously...what do you think somebody reading this is going to do about it (other than LOL with tears in the eyes) ---???