Abstract: The heat treatment apparatus comprises at least three, preferably four, infra-red radiators with arcuate linear heating elements. Two radiators are arranged laterally and one, preferably two, central radiators are arranged above the human head. A support arm is displaceably mounted on a ground stand or a wall bracket. The radial median axes (26) of the lateral radiators (6) include between them an angle (.beta.) of at least 80.degree., preferably 108.degree.. The ratio between the length of each linear heating element of the radiator, preferably comprising a quartz glass tube, and its radius of curvature (R) amounts to at least 0.2, preferably 0.6. Preferably, the radial median axes of the two central radiators include between them an angle (.gamma.) of at least 45.degree., preferably approximately 68.5.degree., the lower central radiator (9) preferably being swingable downwardly through preferably 30.degree. for the treatment of hair of shoulder length.