Abstract: A process for producing a heat delivery device containing or consisting of a polymer composition comprising a fragrance or part thereof comprising the steps of: a) producing a first polymer composition, by feeding a thermoplastic polyester, optionally a first thermoplastic copolyester elastomer and optionally further components of the composition to an extruder, melting and mixing the components, b) cooling down the first polymer composition and c) feeding the first polymer composition and a master batch comprising a second thermoplastic copolyester elastomer and the fragrance to an injection molding machine, melting and mixing the first polymer composition and the master batch in the injection molding machine to obtain the second polymer composition and injection molding of the so obtained molten second polymer composition into the mold of the high-heat delivery device or the part thereof.