Abstract
The low heat transfer through firefighters' protective clothing (FPC) to the exterior is thought to be one of the contributing factors to heat stress in firefighters. In order to describe the heat transfer characteristics of FPC, we measured the thermal resistance (TR) of FPC quantitatively by using a movable thermal manikin. To estimate the effect of clothing size on TR, we used M, L, and LL sizes of protective clothing. To simulate the clothing that the firefighters wear at work, we put work clothing (WC) under the FPC, and placed gloves and long boots on the manikin. We also estimated the effect of the length of WC trousers on the overall clothing TR. When the manikin was standing still, the size of the FPC did not affect the overall thermal resistance. When the manikin was walking, however, the LL FPC proved to have less thermal resistance than either the L or M size, presumably because a larger amount of air moved into and out of the LL FPC. When wearing FPC over WC, the larger sizes had a larger TR when standing still. Wearing short trousers under the FPC had little effect on the overall TR and, since wearing long trousers under the FPC was reported to reduce burning on the legs, the change from long trousers to short trousers did not seem to be beneficial.
