Aida64 - File>Preferences>Alerting>New, Alert Trigger>choose sensor and temp, Actions>Shut down system.
HWInfo64 - Sensors>Configure, Select sensor, Enable Alerting, If Value > *Your Temp*, Run a Program "Shutdown.exe /s /f" - you'll need to experiment, I've not tried it as I have Aida64. The /s and /f are for a forced shutdown (apps are immediately closed), You may get issues with permissions if not run as an admin. You may need to run a batch file if HWInfo is unable to add the /s /f switches.
SpeedFan - Configure>Events, If "sensor" > "Your Temp" then "Execute" "Shutdown.exe" "-s -f", again can be problematic with permissions, I found the easiest way to get another "Shutdown.exe" and take full control of it and execute that.
Edited by Darren9 - 5/9/12 at 10:53am