What does temperature measure?
temperature measures kinetic energy or the energy of motion.
degrees Kelvin known as absolute temperature assumes that at zero degrees Kelvin (-273 ##C^o##) that there is no kinetic energy measurable.
If there was no kinetic energy electrons would stop moving the electron clouds bound by the electron energy shells would collapse and the atoms were become like tiny dust.
There would be no useable matter in the universe. The stars themselves would collapse in to almost nothing.
So the higher the temperature the greater the kinetic energy and the more motion there is in electrons, atoms and molecules.