Try maintenance mode, it may let you. To get into maintenance mode there is a bios config jumper you will need to move it to pins say 2-3 if normally it is on 1-2. Also see what you fan and heatsink are like are they very dirty?
After I replaced the heat sink and cpu fan (cost me $20), it's working fine now. Somehow under BIOS I don't see where I can adjust the threshold temperature?