ASL supports both the lm_sensors package and the ACPI system to let you look at the CPU temperature if your motherboard supports the function.
If the motherboard reports reading the temperature through ACPI you will have this file:
If it does not you can try lm_sensors, to set it up you will need to disable asl-mod in init.d:
Step 1) Allow modules to be loaded
Then follow the dialog from this utility, if sensors are detected it will tell you, after that you can read them with:
Step 4) reenable the security policy
asl -m kernel_check.sh -f