Are you using an OC program, My 2 referance 560Ti's Idle around 38C top and 35C bottom , when I installed afterburner and set up a OC profile My temps stayed high because it was forcing voltage thru my cards all the time.
the fix , I set up profile #1 to stock settings and locked it to 2D applications, than I set up profile #2 for my overclock and locked it to 3D applications.
now when browsing the web or watching youtube videos(when you don't need alot out the cards) the run at stock referance clocks and voltages, and the normally stay under 40C, when you load a game afterburner loads in profile 2 and the temps rise to 50-70C depending on the game but thats normal.