insolation vs sunstroke

insolation and sunstroke both are nouns.

Word	Noun	Adjective	Verb	Adverb
insolation	Yes	No	No	No
sunstroke	Yes	No	No	No

As nouns, insolation and sunstroke are synonyms defined as:

insolation and sunstroke: sudden prostration due to exposure to the sun or excessive heat

Other synonyms of insolation include siriasis, thermic fever.

insolation (noun)	sunstroke (noun)
therapeutic exposure to sunlight	sudden prostration due to exposure to the sun or excessive heat
incident solar radiation
sudden prostration due to exposure to the sun or excessive heat