My latest hobby project has been restoring a Dell Latitude C600 laptop that was given to me. After upgrading the hard drive, processor, and even installing some missing machine screws for it, it has become a decent machine for accessing the Internet around the house. Usually for fan and temp monitoring I use Speedfan which is an excellent utility. In this case though, I found I8fanGUI, which is made specifically for Dell laptops. If you have Dell laptop, you should check to see if your particular machine is on the supported list.
Note that this software is Use at your own risk and is not supported by Dell. According to Christian’s site, the fan control code is part of the Linux kernel now.