I just got my iPhone 6+and setting it up. I have noticed it has heated up very quickly. I have had every iPhone series and this is the first I have noticed one heating up so quickly. Any one else notice this?
A lot of people have reported this when setting up their iPhone 6. But I haven't seen anyone report heat issues after the first day. It has to do with a lot of network activity and CPU activity related to moving a lot of files around and indexing them. If you still have the problem after a day I would say look into it, but chances are, it won't be a problem. I have zero heat issues with my Plus so far (since Friday).