hotness vs warmth

hotness and warmth both are nouns.

Word	Noun	Adjective	Verb	Adverb
hotness	Yes	No	No	No
warmth	Yes	No	No	No

As nouns, warmth is a hyponym of hotness; that is, warmth is a word with a more specific, narrower meaning than hotness:

Other hyponyms of hotness include calefaction, incalescence, fieriness, red heat, torridity, warmness, white heat.

hotness (noun)	warmth (noun)
the presence of heat	a quality proceeding from feelings of affection or love
a hot spiciness	the quality of having a moderate degree of heat
a state of sexual arousal	the trait of being intensely emotional
	the sensation caused by heat energy
	a warmhearted feeling