Pyro... the thing without a face (1964)

A married man has a brief affair, then goes back to his wife and children. His jilted mistress, believing that if he had no more family he'd come back to her, sets fire to his house, hoping to kill them. The man, unsuccessfully trying to rescue them, is horribly burned. After he undergoes an operation to reconstruct his face, he begins to plot his revenge against his former mistress.