Odd, mine is idling at 49 C in a 21 C room. This is the 4G version running fully updated Raspbian without the desktop (one of the updates fixed the USB controller using a lot of power at idle).
Mine is 4G too; I installed heatsinks on it couple hours ago and it now sits at 61°C idle, with an external HDD attached (but not under I/O load) to USB 3 port. Slightly better, though arguably still ridiculously high.