iPhone XS completely unresponsive

Hello,

I was using my iPhone XS and it was working normally while browsing through Snapchat. I closed the app, then turned the screen off. A few minutes later I re-opened the phone, it opened to safari, and promptly "froze". The phone itself wasn't entirely unresponsive, I could press on the search bar and it would highlight the website URL at the top, but the text keyboard would not pop up as usual. No websites would load although I could tap on the "favorites" websites in the safari main screen which would bring the respective URL to the search bar. The screen would not turn off when pressing the power button, and trying to exit the app, pull down the notifications window, or pull down the quick-access services window would not work. The phone would not respond to my attempts to force restart/shutdown, and after about 5 minutes of the aforementioned functions working, the phone became completely unresponsive to all inputs (touch and button). Even taking the sim card out had no effect. The phone is still powered on, stuck in safari, and very warm to the touch. How do I fix this?