My Lenovo Y560 laptop started to over heat few days back. Here is simple fix (clean CPU fan).
Cleaning had lowered my CPU temperature quite a bit.
If this does not work for you, option 2 (from google search)
BIOS 71 > Some users reported heat problems after upgrading to the new BIOS version 71, since it seems that the fan speed is bugged in this version and downgrading to an older version should help.
A nice software to monitor Y560 temperature Link