Do you perspire, or do you sweat?
Perspire derives from the Latin spirare, "to blow" suggesting vapors released by the body. It emerged in the 1600s as a gentler alternative to the much older word sweat.
To some, perspire sounds more refined; to others, it seems a bit precious. As one London magazine reported in 1791,
"It is well known that, for some time past, neither man, woman, nor child, in Great Britain or Ireland, of any rank or fashion, has been subject to that gross kind of exsudation which was formerly known by the name of sweat; and that now every mortal, except carters [and] coal-heavers... merely perspires." (The Gentleman's Magazine, Volume 70)