Local body warming is often necessary to protect wearers in cold weather. Concerns for partial heating with tight inner wear, however, are still lacking.
In this study, human responses due to abdominal heating pads were observed when pattern reduction rates of a base layer varied from a tight fitted compression style (garment A) to a very loose one (garment D).
Ten male subjects participated in the experiment with four sizes of experimental garments under the condition of 2℃, 60% RH, 0.1m/s. Subjective evaluations due to the attached heating pads on the different sizes of base layers were reported using 7 or 9 points scales. Chest, abdomen and scapula skin temperatures and microclimate were also measured.
It was found that the tighter the pattern (i.e., pattern A), the warmer the abdomen both in subjective sensation and skin temperature, which did not affect the differences in skin temperature of torso. Eventually, however, chest temperature decreased, while temperature of abdomen increased during the heating periods, indicating that heating with the heating pads was not enough for whole body warming in this study.
As a result of thermogram analysis, surface temperature of the experiment garment D showed the lowest, implying that ventilation could be easily occurred in the space between the human body and garment D due to the large space between body and garments. The garment D was not suitable for local warming of abdomen. The thermal sensation reactions of garments A and B were ranked high, but clothing pressure of A was evaluated bit high for the wearers in this study. It was noted that pressure sensation and contact sensation improved when the abdomen was heated in a cold environment.
Overall, for the desirable heating of abdomen, the ease of base layer needs to be within the size limit of the abdominal circumference as in the case of garment A and B. Depending on the wearer’s preference on the compression level, the optimal garment could be either A or B. For persons who concerns appearance, the garment A was suggested, and for those who want rather comfortable fit, garment B was better.