cool down vs change state

cool down and change state both are verbs.

Word	Noun	Adjective	Verb	Adverb
cool down	No	No	Yes	No
change state	No	No	Yes	No

As verbs, change state is a hypernym of cool down; that is, change state is a word with a broader meaning than cool down:

Other hypernyms of cool down include turn.

cool down (verb)	change state (verb)
make cool or cooler	undergo a transformation or a change of position or action
loose heat
lose intensity