Hong Kong is often playfully called the “Frozen City” because the air-conditioning in many buildings operates at frigid temperatures during the summer. However, the large temperature differences between the external and internal environments could cause a large array of illnesses, especially children who are not aware of the temperature changes and are less likely to have self-care ability. Therefore, wearing appropriate undergarments or summer underwear could be one of the solutions. However, there are few studies that have investigated the thermal and tactile comfort of summer underwear. In this study, physical experiments, KES-FB measurements, and a wear trial are done to address the lack of studies. Seven conventional types of materials for undergarments are tested. The results indicate that lighter, thinner, and low stitch density fabrics constructed with uniform filaments increase breathability and enhance moisture wicking. Also, uniform fibres increase the thermal conductivity thus enhancing a cooler feeling. In regards tactile comfort, lighter and thinner materials with a higher percentage of elastane, finer yarn, and uniform and long fibres offer a softer, smoother, and cooler hand feel. In addition, the pure cotton material appears to more regulate body temperature as the resultant undergarment facilitates a higher rate of perspiration despite clinging. These results are a good reference for materials scientists, textile researchers as well as academics to further related research work.
