Like JoeHead said, if you list your motherboard, someone may be familar with it. Perhaps it comes with its own monitoring utility? However, I know of no way to control the temperature aside from making sure you have a good heatsink/fan.
With that said, I *think* there's a program called something like "cpuidle" that will slow down your cpu when you're not "using it" that much, but I know nothing about it.
A good, free monitoring program with various alarms, called Motherboard Monitor, can be downloaded at:
<A HREF="http://mbm.livewiredev.com/" target="_new">http://mbm.livewiredev.com/</A>
I'm using 4.18 and haven't tried 5.x yet.
Mike