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 of the lateral radiators include between them an angle of at least 80 °, preferably 108 °. the ratio between the length of each linear heating element of the radiator , preferably comprising a quartz glass tube , and its radius of curvature amounts to at least 0 . 2 , preferably 0 . 6 . preferably , the radial median axes of the two central radiators include between them an angle of at least 45 °, preferably approximately 68 . 5 °, the lower central radiator preferably being swingable downwardly through preferably 30 ° for the treatment of hair of shoulder length . owing to the arrangement and construction of the infra - red radiators as well as the use of an optical location device for the head , a uniform temperature distribution on the hair as well as facilitation of operation can be attained .