Overheating device with random apps spiking CPU usage Few days ago my phone has started overheating and burning through the battery like crazy. I don't use it too much, and it used to last 1.5-2 days, now it's dead in 6 hours. 

I've installed System monitor lite and it's showing that several of my cores are constantly at extremely high usage (over 80%), and various regular applications like Gmail and LinkedIn are shown spiking the CPU up to 20% each. I expected a single app to be doing something stupid, and after seeing which one it is, it would be simple to just remove it, but that's not the case. It turns out that a bunch of regular apps that I haven't opened in days are going crazy. 

Here are some screenshots:






So, any suggestions besides doing factory reset?

The phone in question is Xiaomi Redmi Note 4 running original MIUI without root.
A couple of things: 


Applications that show running processes are only able to show the user processes (meaning no kernel processes)
Android gives more priority to the application in the foreground (the one you are currently seeing). When you open the the task manager, the other processes are being capped. The measuring you are trying to do influences the results.


If you can provide more details by measuring externally with one of these:


Try installing Android Studio:
Post the Log Cat results: 
Or use the Android Debug Bridge (adb) with adb logcat – you can view your Android device’s log.


With one of these you can actually profile your running Android phone over a USB connection.

I don't think anyone can give you a complete direct answer without some more information, except if maybe they had the exact same model number and issue.