Please note that there is a known memory leak issue caused by MS. Read this KB
article: KB893317

I assume the user is familiar with WMI and has already set up his/her machine to compile WMI projects. if not, then check Set Up Delphi For WMI

Get the system and cpu temperatures on the local machine using WMI in Delphi

Note: works with GigaByte mainboards. maybe others, don't know. This depends if the mainboard manufacturer has included WMI adapter/classes with the driver installation and obviously will need to adapt the wmi class name for the specific WMI adapter. Note that gigabyte at the time of this writing did not implement the general temperature reading classes/methods available in "standard" WMI.

Source Code