Research Highlights the Importance of PPE Moisture Barriers in Managing Firefighter Heat Stress

ELKTON, MD—Although firefighters need protection against extreme heat, the vast majority of calls do not involve this kind of challenge. Instead, managing heat stress is often the real challenge. W. L. Gore & Associates, Inc. studied the effects of working in warm conditions and those with low-level radiant loads such as from the sun, asphalt highways, rooftops, and even fireground sources, which often pose significant heat stress challenges. Currently the Total Heat Loss (THL) test in the NFPA 1971 Standard only considers a single, relatively mild condition in its assessment—similar to a moderate spring day in the shade.

According to Allen Maples, product manager within Gore’s Technical Fabrics division, “The human body is extremely sensitive to seemingly small increases in core temperature, and these increases can potentially lead to impaired decision-making and heat exhaustion events. The ability for turnout layers to allow greater moisture vapor transmission for evaporative cooling to take place is key to preventing the rise in body core temperatures. Gore evaluated the performance of turnout gear in warmer and low-level radiant conditions, for example when exposed to the sun, and was able to link the heat loss ability of various turnout technologies to the performance in a garment and the impact on the wearer.”

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