Well i can asure you that all snapdragon 800 soc overheat and it depends on what you do,my curent device lg G2 when i bought it,it had jellybean on it whne browsing web listening to music etc it always got hot,but when plating games it was a very big overheating ,the procesor got up to 72`C ad baterry was on 42`C and i thought it was a problem with the phone but after updating to kitkat all problems with overheating where gon even in graphinc intense games it took the phone 30 minutes to heat up significantly + on a side note the battery got a lot better i managed 4 hours and 36 minutes of screen time.
Botom line its a software problem coupled with the nano coting(it blocks heat but not in a bad way that the phone will overheat from that maybe a 5`C block).