I'm not sure what's going on, but sometimes my phone gets super hot. It's almost unbearable to hold when it gets hot. It isn't dependent on where I am; outside, inside, etc. Sometimes I'm listening to Apple Music, surfing the web, social media, etc. I'm not editing in iMovie or anything strenuous. Sometimes it's hot the touch just sitting on a table. What should I do?
Are you connected to a charger when this is happening? Heat = energy usage. Go to Settings > Battery to see what's using the power. Have you done a restart since this began?
Nothing is running in the background. It heats up when its not charging. Its almost 3 years old. They probably won't replace will they?
Pledge your case that it isn't a physical damage done by you. Give all the other crap reasons so they can replace it. Just before you go in, make the phone very hot, so they can feel it themselves. They won't want any case like the Note 7.
I called Apple Care. They said I should restore my phone after they received the hardware diagnostic.
Do it for the sake of doing it. Then tell them it didn't work a simple bit. Tell them the phone feels so hot you could cook an egg on it. Be intense in your language.
Do a full encrypted backup with iTunes and reset the phone as new and use it for a day. This will tell you if it is a hardware problem or one of your apps misbehaving.