The purpose of this study was to develop a warm-up suit that is comfortable as well as having a good thermal performance. Heat-insulating water vapor-permeable fabrics for warm-up suit were developed by applying ceramic powders to hydrophilic polyurethane films, which were then incorporated into textiles. Two types of ceramic compounds were used in this study: MU-4N and RT-3. The infrared emissivity was 92.6 for MU-4N and 94.8 for RT-3. In order to evaluate the effectiveness of using ceramics in a warm-up suit, we examined the effects of ceramics on selected variables: thermo-physiological properties of the clothing systems (using thermal manikin), and thermo-physiological responses and subjective sensations of human subjects. The infrared emissivity of textiles increased when ceramics were added to the film laminate. Ceramics slightly increased the thermal insulation value and decreased the water vapor transmission rate. The thermal manikin test also showed that ceramics enhanced the thermal insulation of the clothing system without increasing the evaporative resistance. The microclimate temperature was kept higher when subjects wore the warm-up suit with ceramics.