If it gets hot then just unplug it and leave it until you come to fix it, the battery will probably run out and then there’s no issue of the heat, you can always charge it back up when you come to fix it.
First thing if you haven’t already tried hold the volume down button and the on'/off button together until the screen goes black and turns back on again with the apple logo.
If you still have the issue where it is stuck on the apple logo you will need to either try connect to iTunes on a computer, call apple support or start taking the phone apart and fixing it yourself.