You see, my friend, the RAM is not the only thing temporarily storing tasks here. The CPU has it's own cache reservoir as well which is the primary co-pilot to the CPU...long explanation short, this cache is supposed to transfer instructions to the CPU but is having great difficulty doing so, because unlike Windows, Android will keep tasks inside this cache for quick opening which unfortunately causes overheating easily. To get to the Task Manager and remove all of these unnecessary tasks, you can hold down the Home button from any screen of your phone and you should see a list of programs such as Facebook, YouTube, etc. which is the list of programs you have opened since you last turned the phone on. (If you don't have an S4, it may or may not be different...most times holding Home does work though.) Look at the bottom right corner of the screen and you should see an icon that looks like a trash can in front of some horizontal bars. This will clear all of the tasks currently inside this list and will help your CPU immensely. The Task Manager is a great multitasking tool as well...you can google "How to use Android Task Manager" for more information.