cold snap vs while

cold snap and while both are nouns.

Word	Noun	Adjective	Verb	Adverb
cold snap	Yes	No	No	No
while	Yes	No	No	No

As nouns, while is a hypernym of cold snap; that is, while is a word with a broader meaning than cold snap:

cold snap: a period of cold weather
while: a period of indeterminate length (usually short) marked by some action or condition

Other hypernyms of cold snap include patch, piece, spell.

cold snap (noun)	while (noun)
a period of cold weather	a period of indeterminate length (usually short) marked by some action or condition