iphone 7+ heating near camera

Hi all

I am using iphone 7+ since Jan'18 and recenetly I've noticed that whenever I watch videos/movies/using whatsApp/maps/browsing/playing games or use apps that involve using the camera, the back (mainly around the rear camera) getting hot and in some cases it is difficult to keep in hand! I was thinking it might be a battery issue but the entire back doesn't get hot, only the camera or near the camera - the rest of the back is normal temperature, Anyone know of a solution to this? All help is much appreciated. 🙂

iphone details:

- iphone 7+

- iOS version: 11. 2.6

FYI- recently LTE launch in bangladesh and my SIM card is not updated to USIM as the network is not ready for LTE/Apple recomodention parameters are not implemented in the network.

does it cause of this?

cheers!