AbstractA test device consisting of an asbestos covered wooden cylinder was developed to study the burning behaviour of textiles relative to transmitted thermal energy and heat flux registered at 20 sensor points on the cylinder. In order to simulate a ‘line situation’ a reproducible procedure was used for igniting the fabrics at the hem edge by open flames. By linking known tolerance thresholds for second degree burn injuries in humans to the measured time patterns of transmitted thermal energy, the burning behaviour of a pure cotton twill, a 35/65% polyester‐cotton twill and a 65/35% polyester‐cotton twill was compared. All fabrics, which had no fire‐retardant finishes, were also tested in combination with cotton underwear and in some of the experiments they were soaked with an inflammable solvent before ignited. In contrast to customary opinions it could be shown that in apparel burn accidents without inflammable solvents fabrics made from polyester‐cotton blends are more advantageous with regard to the thermal energy transmitted to the skin of the wearer than fabrics made from cotton. Even when the burning clothes are soaked with an inflammable solvent, polyester‐cotton blends are practically not more disadvantageous than 100% c