heighten vs hot up

heighten and hot up both are verbs.

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

As verbs, hot up is a hyponym of heighten; that is, hot up is a word with a more specific, narrower meaning than heighten:

Other hyponyms of heighten include heat up, screw up, fan, enhance, heighten, raise, amplify, sharpen, heighten, sharpen.

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