CPU throttling on demand

Hi,

Working on a hardware solution for a client, will be running from solar/battery and in a hot enviroment hence need to keep the heat down however possible.
They want the flexibility of power when needed, currently thinking of using the N3350 or N4200 processor.

And looking for a solution to ensure the processor performance is limited during extreme hot days. Understand hardware throttling can kick in to control extreme heat, but this is really too little too late. I simply don’t want to run hot if not needed.
My knowlegde of Linux/NixOS is limited, is it possible to throttle the processor on demand?

Rob.