Heck was born in the Jamaica neighborhood of Queens, New York City, the son of Bertha and John Heck, of German descent. Heck learned art through correspondence courses as well as at Woodrow Wilson Vocational High School in Jamaica and at a community college in Brooklyn. He continued with an impromptu art education in December 1949 when at the recommendation of a college friend he landed a job at Harvey Comics. There he repurposed newspaper comic strip Photostats into comic-book form — including the work of Heck's idol, famed cartoonist Milton Caniff.