hot up vs heighten

hot up and heighten both are verbs.

Word	Noun	Adjective	Verb	Adverb
hot up	No	No	Yes	No
heighten	No	No	Yes	No

As verbs, heighten is a hypernym of hot up; that is, heighten is a word with a broader meaning than hot up:

Other hypernyms of hot up include compound, deepen, intensify.

hot up (verb)	heighten (verb)
make more powerful	increase the level of
make more intense	become more extreme
gain heat or get hot	make more extreme; raise in quantity, degree, or intensity
	make more intense, stronger, or more marked
	make (one's senses) more acute
	increase the height of