Heat is a major enemy of electronics. The CPU of any modern computer has thermal sensors that will either throttle back or shut down the data flow if temps get too high. Even going to the extreme of shutting down the system! Many high-end video cards also have GPU thermal sensors that throttle back or suspend activities.
About 75% of input current to a computer system is wasted as heat. That heat must be disposed of, to keep the system optimally active. Small fans do work well, but their design and placement allow unwanted warm air to be recirculated causing higher temperatures. A case fan blowing toward the CPU and GPU will help disperse that unwanted heat. The desired ratio of air flow in a case is 1.5:1, more air incoming than exhaust. The PSU is a major heat source also, and needs a lot of cooling air.
Background programs also take away CPU cycles needed for data sorting and routing. Unneeded programming running in the background can waste CPU cycles. End those 'finder', 'update' or "IM" programs. They will still be available when needed. Run a 'lean' system, get better performance. But never terminate your antivirus or firewall programs! The OS update program should also be always active, but you choose when to install those updates.
F@H.. to solve mankind's maladies.. in our lifetimes!