Why is the top right corner of my iphone gettiing so hot its an iphone 4?

Why is the top right corner of my iphone gettiing so hot its an iphone 4?

The top right corner is where the GPS chip is located on the motherboard, This is the most power hungry chip in the phone and some apps can turn this on (for location) and leave it on, go to settings and look for location services, there will be a list of apps the use the GPS and a purple arrow will be beside any apps currently using it, uncheck these and see if it helps