Elasta produces elastic and non-elastic narrow fabrics. Within that range of products they are constantly striving for new innovetions. In that context there have been several contacts with the Dept. of Textiles of Ghent University. Through this contact Elasta was acquainted with the search for a partner to manufactre a textile-based heat flux sensor. From natural phenomena to industrial applications, phase change plays an important role in many fields. The evaporation process or the transformation of liquid into gas, or inversely, undergoes a phase change without a difference of temperature, and is characterized by the latent heat coefficient at constant pressure. Due to thermo-physiological dynamics, the wearer’s thermal comfort depends on his/her clothing, since garments can be an obstacle for heat and moisture transfers. Due to thermoregulation, at high activities or in warm conditions, fast accumulation of sweat in the clothing generates thermal discomfort, up to burn injuries in extremely hot conditions for firefighters PPE’s.