Influences of moisture management performance and continuous sweat rate on heat transfer through firefighting clothing under radiant exposure

Abstract

Human continuous sweating can adjust the thermal protective performance (TPP) of clothing for firefighters by controlling moisture distribution and transfer, which can provide extra thermal protection or injury. To accurately evaluate the heat transfer performance, a calibrated sweat simulant sensor was applied to investigate the influence of moisture management performance (MMP) of materials on the TPP under continuous sweating at a low-level thermal radiative intensity of 8.5 kW/m2. The results revealed that the dual role of continuous sweating on the TPP depended on sweat rate, fabric layers, material properties of the inner layer, and exposure time. The MMP could reduce the heat transfer performance at a high sweat rate for prolonged work, leading to a maximum decrease of absorbed thermal energy up to 16.93% and 49.03% for single and multi-layer fabrics, respectively. The second-degree skin burn occurred in half of the exposure process, and the skin burn time was reduced by up to 5.57% for multi-layer fabrics with good MMP due to the limited increase in thermal conductivity during initial exposure. This study provides a more comprehensive understanding of accurately assessing thermal damage and offers some guidance for selecting the inner layer materials of firefighting protective clothing for various firefighting conditions.