Method of treating hair fibers, without complementary application of a composition containing a chemical oxidant, characterized in that it comprises the following steps: - application on hair fibers of a reducing composition without ceramide, which contains at least one thiolated reducing agent and at least an active cosmetic agent, the active cosmetic agent (s) being selected from the non-polymeric active agents selected from the waxes, anionic, cationic, non-ionic, amphoteric or hybrid ion surfactants, anti-fall agents, antipelicular agents, sequestering agents, opacifying agents, dyes, sunscreens, vitamins, preferably vitamins A, B3, B5 C, E and F, provitamins, preferably provitamin B5, fatty acids, fatty alcohols, esters, pearly pigments, mineral, vegetable or synthetic oils, as well as perfumes and preservatives and mixtures thereof, comprising the composition r educates one or more solvents selected from C1-C6 alcohols, preferably alkanols such as ethanol, propanol and isopropanol, polyols such as propylene glycol, pentanediol and glycerin, and polyether ethers, - temperature rise of hair fibers, by means of a heating plate, at a temperature at least equal to 60 ° C, the temperature being raised before or after the optional rinsing of the hair fibers.Procedimiento de tratamiento de fibras capilares, sin aplicación complementaria de una composición que contiene un oxidante químico, caracterizado porque comprende las siguientes etapas: - aplicación sobre las fibras capilares de una composición reductora sin ceramida, que contiene al menos un agente reductor tiolado y al menos un agente cosmético activo, seleccionándose el o los agentes cosméticos activos entre los agentes activos no poliméricos seleccionados entre las ceras, agentes tensioactivos aniónicos, catiónicos, no iónicos, anfóteros o de ion híbrido, agentes anticaída, agentes antipeliculares, agentes secuestrantes, agentes opacificantes, colorantes, filtros solares, vitaminas, preferiblemente las vitami
