What am I talking about? How heat is generated? Are you okay Micro? That's self explanatory! It heats up because you use it. It's that simple! It just that....
Of course I know how heat is generated. What I'm saying is how it is generated scientifically.
Okay lets start by the most common thing that generates heat, Energy.
Energy as we all know cannot be created nor destroyed but, it only transfers to other energies or transformed. Energy is coming from power which is the electrons that flows through your device. Now, the amount of electrons required to power up a component depends on how much ohms or resistance that conductor has. The grater the resistance, the greater amount of electrons which means more power and more energy. As it travel through the conductor, power generates heat energy that's why it creates heat. The more power, the more heat. Now you getting the point? If there are no resistance, then there would be no heat because lesser power is required.
Is there ever a conductor that have no resistance? Yes there is! Some group of researchers and scientists are developing something that doesn't have any resistance. That can be the future of computers which means, no more heat output and throttling! But in order to achieve the no-resistance state, the "thing" must be in absolute zero temperature. That's the main objective now, how to sustain absolute zero temperature without the assistance of cold environment.
If you wanted to know more, search Superconductivity.