Iphone is stuck on notification screen

IPhone screen is stuck on notification screen, I can not scroll back up or go to the home page. It will only allow me to go from "today" to "notifications". I can not restart the phone because it will not allow me too. I don't know what to do. I was able to get this screenshot by retrieving it from my I cloud account. What should I do? I was thinking maybe let the phone run out of battery and hope it restarts from there, but I don't know if this will work.