Certain workloads can't just magically cause your CPU to get "unusually" hot. It's true that some instruction sets can cause greater thermal loads than others, but disabling the relevant instruction sets is only likely to make it worse, as the CPU will then complete the work using other less efficient instructions.

A CPU will run as hot as it needs to to do whatever it is doing, up to whatever its safe temperature is, at which point it will slow down to protect itself. Running at this "max" temp is not a problem. CPUs will run as fast and hot as they safely can, and no hotter.

Presumably the emulated games are simply framerate and resolution limited, where the normal PC games may not be.

That said, there are some things you can do, assuming the CPU doesn't actually need to work as hard as it is to run the games you are playing.

• Limit framerate. The game may be running uncapped, in which case it will be using 100% GPU (and therefore more CPU as well) to create as many frames as possible. The ones in excess of your display refresh rate will simply not be shown. You can usually limit framerate in game settings (often called vsync). If this isn't available, it can be done using mangohud.
• Limit power and/or clock speed. This will lower power consumption and temperatures, at the cost of performance. Which is not a problem if the game doesn't actually need to run that fast.
• Lower the "max" allowed temperature. This will cause the CPU to throttle sooner, keeping it cooler. This usually has a severely negative impact on performance.

You might also look into undervolting the system. This involves lowering the voltage used by the CPU. This can allow it to run cooler without sacrificing performance, but can cause system instability.