You probably wanted a low thread priority/QoS setting. The OS knows how to run threads such that they don't heat up the CPU. Well, on modern hardware it does anyway.
I’d expect any os worth it’s name to run threads in a way that minimizes total energy not fan noise.
The OP did say this was circa 2010. So we're talking 15 years ago.
I’d expect any os worth it’s name to run threads in a way that minimizes total energy not fan noise.