Effect of a Lightweight Structural Firefighter Turnout Composite on Physiological Comfort
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Published:2020
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This research investigated the impact of a novel lightweight turnout composite on the physiological response and comfort of structural firefighters during intense physical activity. Lighter weight materials were incorporated into a prototype turnout suit. Four ensembles were evaluated for physiological response and comfort: (1) a lightweight (LW) prototype, (2) a traditional turnout suit (Control), (3) a single-layer (SL) outer-shell garment, and (4) a base layer (BL; t-shirt and shorts). Ten male career firefighters participated in a human wear trial, which involved wearing all four test garments (LW, Control, SL, and BL) in two test conditions: graded exercise test (GXT) and a firefighter simulation exercise (FFSE). For the GXT, participants ran for 2 min at a 0% grade for each of three predetermined running speeds before the incline was increased by 2% every 2 min until volitional exhaustion occurred. For the FFSE, participants were asked to perform realistic firefighting exercises, including a hose carry, dummy drag, weighted rope lift, stair climbs, and tire flips. Peak oxygen consumption (VO2peak), blood lactate, intestinal core temperature, skin temperature, sweat rate, and heart rate, were measured during both test conditions, with the exception of VO2peak, which was collected during the GXT only. Subjective thermal comfort assessments (perceived exertion, thermal sensation, and comfort) were also collected for all test sessions. The relationship between material weight, ensemble weight, and physiological strain was analyzed. No significant differences were found between the test ensembles for core temperature, skin temperature, or heart rate. Findings indicate firefighters experienced similar levels of physiological strain, regardless of turnout suit material weight, during both exercise protocols. Significant reductions in heat strain may require whole-garment layering modifications as exhibited by the SL ensemble, which significantly extended the time to volitional exhaustion, reduced subject weight loss during the GXT, and lowered skin temperature during the FFSE.