hot up vs modify

hot up and modify both are verbs.

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

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

hot up (verb)	modify (verb)
make more powerful	make less severe or harsh or extreme
make more intense	add a modifier to a constituent
gain heat or get hot	cause to change; make different; cause a transformation