CPU 100 degrees celsius when running Sims 4

@CrazySheep808  I don't think the issue is that your laptop isn't powerful enough for Sims 4 overall.  After all, the game runs okay on low-end computers, usually without overheating them too much.  But your fan itself may not be working properly.  50º when idling is a bit high, although maybe the fan doesn't run below a certain temperature.  Still, it's worth making sure the fan itself is functioning and that the vents are also clear.

It's possible that the thermal paste between the processor and the cooling apparatus has dried out too much to be useful, especially given the age of the laptop.  In that case, you'd need to take apart the laptop to clean off the old paste and apply a new coat.  A computer repair store should be able to do it for you.

It's also possible that Origin itself is overworking your CPU.  Try putting it in offline mode before launching the game.

You can try turning down the lighting setting as well.  That's more CPU-intensive than other settings.

Thanks for your suggestions - I have tried putting origin in offline mode, which made no difference, but I will get the thermal paste replaced and see what happens.

Have a good day!