Android Phone Overheating And Battery Drainage

I have the One Plus One Phone and I’m in general happy with the phone but over the last couple of month I noticed that my phone is getting hotter and hotter, especially around the camera and the battery is draining faster and faster. Now towards the end, the phone got almost boiling hot and the battery only lasted 4 hours! WHAAT!
Now as you can see in the picture above, I managed to fix that problem and my phone runs faster than ever and the battery lasts over a day now.
How did I do that?