iPhone 7 Plus getting hot

I bought a new iPhone 7 Plus last week. I activated it Wednesday, April 24. It has only been in ~ light ~ use for 5 days. I have only used the new charger included in the box. I notice the phone getting hot after only using it for about 8- 10 minutes. It gets hot while charging. I haven’t even put the protective case on yet, and now I’m worried that it might make the phone hotter. I’m really upset to be having this problem with a brand new phone. I’ve tried turning off unnecessary features like Bluetooth and location services. I usually only have one or two apps running. Should I try to return this phone?? Do other iPhones have this problem??? Just a quick google search about this and then typing here, it’s super hot in my hands. I’m indoors in the AC, for pete’s sake!