Temperature System How and why do we control heat on a spacecraft?

Why does heat make the electrical system less efficient?

Electricity is caused by the flow of electrons (the smallest part of an atom) through a conductor of some sort, usually metal wire, but there are other substances that allow electrons to flow. Electrons move through the atoms of the conductor. Generally, one electron will enter the electron cloud of an atom, and another one will leave, continuing the flow of electrons through the conductor.

When a solid is heated up, the atoms in it move around. This means that the electron clouds will not be in the same place all the time, and sometimes an atom's nucleus will "get in the way" of the electrons streaming through the conductor. Also, if an atom is heated up, it can hold more electrons for a longer period of time before sending the extra electron or electrons away and continuing the electrical flow.

Why do we have to control heat on a spacecraft if there are no people on board?
What could go wrong on DS1 if there's too much heat?
How is DS1's heat balance maintained?
How does heat move?
What is an atom?
What is an ion?

How are atoms charged?
What does electrically charged mean?

Why does electrical current make heat?