iPhone Screen help

I was playing on my 5s and it froze and turned white and then I locked my screen and it turned black and I started holding the home button and I heard siri go off and then I reset it and it turned off and it won't come back on. It has did this before but if you know how to make it stop can you please help? I need help I tried connecting it to the computer and holding the power button and home button and moving the notification sound button and using the volume buttons.