I have iPhone 4s and it becomes slowly day by day so I decided reset (format) my phone and reset it as a new iPhone. Then I began to install my essential apps. It's comes to know that my iPhone got unexpectedly shutdown, while making a call, during the conversation with messenger or regular phone call. The iPhone also getting very hot and battery draining very quickly. It was in rather good condition except slow. To make it fast I'm facing this problem. Please help me if there are any remedy?
It's running with iOS Version: 9.3.5 ( 13G36 )