The application of heat in hair styling is a common practice in use today. Thermal styling appliances can reach until 232ºC, thereby, the heat protection is essential for any hair care routine to avoid alteration in the cuticle structure, decomposition of keratin, water loss and hair breakage. This study aimed to develop a thermal protective ingredient based on polysaccharides of Salvia hispanica and trehalose, associated with ethyl esters of sunflower and crambe oils that can be used as a silicone alternative with proven efficacy and safety: ThermoShield N. To evaluate the efficacy, after flat iron exposure, four groups of hair tresses (Control, Placebo, ThermoShield N and Benchmark) were investigated using thermal images, moisture analyzer, AFM and SEM. The results showed that the ThermoShield N provided a significantly reduction in the hair temperature and an increase in hair water content, compared to Placebo and Benchmark. The AFM and SEM micrographs of the fibers treated with ThermoShield N did not show the same signs of damages observed in the Control group. In the experimental conditions the results showed that ThermoShield N is able to trap water inside the fibers and creating a thermal barrier, that protects hair from overheating and consequently, from thermal damage.