Irving Berlin scored numerous great successes on Broadway, prompting Hollywood filmmakers to reuse many of his most popular songs in their musical films. Such was the case with this one, "Heat Wave," which originally appeared in the 1933 Broadway musical revue As Thousands Cheer, but achieved greater exposure when Ethel Merman sang it in the 1938 film Alexander's Ragtime Band, a Darryl F. Zanuck production that was nominated for six Academy Awards and starred Tyrone Power, Alice Faye, and Don Ameche. The song is performed by Merman on-stage in the latter half of the film, with a chorus of male and female singers. The song is sprightly and rhythmic, the perfect vehicle to match the dance movements of the singers in the film. Its ragtime manner and extroverted character unite to produce a song whose catchy aspects relate more to how the music's infectious rhythmic swing suits the slick but clever lyrics: "Her anatomy/Made the mercury/Jump to 93." The last syllable is emphasized in each line here to focus more on Berlin's rhymes. In the end, one must assess this chipper, almost gaudy number as one of the composer's more successful, more cheerful creations. ~ All Music Guide
