I have an Android galaxy 6 edge

[AC Question]

It keeps telling me the CPU is running in the background and it is overheating

 

[TheGoodNamesAreGone]

Try downloading something like Gsam battery monitor to see what might be doing that. Chances are if CPU is affected and the temp is up, battery is likely to be affected too. Also try running in safe mode , if it doesn't overheat in safe mode, an app may be to blame.