The son of a pastor, he attended a grammar school, the Gymnasium zum Grauen Kloster.
His early work consisting, mostly of townscapes and scenes of night-life,[1] shows the influence of his friend, the much older Heinrich Zille, with whom he used to visit the bars of suburban Berlin.
[1] Between 1929 and 1933 he underwent a course of psychoanalysis which prompted him to give up painting, instead making a series of drawings inspired by his dreams.
[1] He moved to Majorca in 1933, but following the outbreak of the Spanish Civil War he returned to Berlin where he shared a studio with the painter Werner Gilles and the sculptor Hermann Blumenthal.
[1] Following his release from captivity, Heldt returned to Berlin, where he painted the scenes of the devastated city which have won him his reputation.