Martha and the Vandellas' version is danceable soul with gospel heat built in. Above the Funk Brothers, a brassy voice asks the question and call-and-response raises the temperature. An early blueprint of the Motown sound.
Linda's version is a light rock arrangement that won out from a B-side through DJ support. Less an attacking beat than a cool, easy groove, rebuilt with careful studio work. The hot soul becomes pop that plays on the radio.
The same “Heat Wave” shifts from gospel-charged soul to a pop-rock that arrives lightly.