fervor vs fever pitch

fervor and fever pitch both are nouns.

Word	Noun	Adjective	Verb	Adverb
fervor	Yes	No	No	No
fever pitch	Yes	No	No	No

As nouns, fever pitch is a hyponym of fervor; that is, fever pitch is a word with a more specific, narrower meaning than fervor:

Other hyponyms of fervor include fever, sensation, feverishness.

fervor (noun)	fever pitch (noun)
feelings of great warmth and intensity	a state of extreme excitement
the state of being emotionally aroused and worked up