Fractional Contribution of Wildland Firefighters’ Personal Protective Equipment on Physiological Strain

Abstract

Activities performed by wildland firefighters are carried out wearing a personal protective equipment (PPE). Although the PPE protects workers from a wide variety of hazards, it may increase their physiological response and limit their performance. The aim of this study was to analyze the effect of the protective clothing (PPC) and the rest of the PPE elements (i.e., helmet, neck shroud, gloves, goggles, and mid-calf leather boots) on the wildland firefighters’ thermophysiological response during a moderate-intense exercise. Six male wildland firefighters performed, in a counterbalanced order, a 120 min graded exercise test wearing three different clothing configurations: (i) a traditional short sports gear (SG), (ii) a PPC, and (iii) a complete firefighters’ PPE. Trials were conducted on separate days at the same time of the day (12:00–15:00 h) and under climate-controlled conditions (∼30°C and ∼30% relative humidity). Heart rate, respiratory gas exchange, gastrointestinal and skin temperature, blood lactate concentration were recorded throughout the tests. Additionally, parameters of heat balance were estimated. Exercise time was shorter (p < 0.001) wearing the PPE (62.4 ± 13.3 min) than with the PPC (115.5 ± 5.0 min) and SG (118.2 ± 20.7 min). The increment of gastrointestinal temperature with the PPE (1.8 ± 0.3°C) was greater (p < 0.05) than the observed in PPC (1.2 ± 0.6°C) and SG (1.0 ± 0.2°C). The use of PPC increased (p < 0.05) subjects’ metabolic demand and skin temperature versus SG during the last 20 min of the test. The sweat retention in the PPE (1,045.7 ± 214.7 g) and PPC (978.3 ± 330.6 g) was significantly higher than that obtained in the SG (510.0 ± 210.0 g). Sweat efficiency decreased (p < 0.05) in the following order: PPE (45.6 ± 18.3%), PPC (64.3 ± 7.8%), and SG (79.3 ± 7.0%). These results highlight the importance of the PPE elements in the subjects’ thermal strain. The reduction in the sweat evaporation produced by the PPE, together with the ensemble mass caused a substantial increase in the subjects’ thermophysiological response. As a consequence the performance was reduced by ∼50%.

Contact-Based Methods for Measuring Respiratory Rate

“…Besides, fR can be used as an indicator of thermal stress because it is substantially influenced by body temperature [21]. This is important for workers operating in hot environments as well as for those wearing protective clothing and equipment that may interfere with thermoregulation, including firefighters [22].…”

Graphene Modified Multifunctional Personal Protective Clothing

“…In heat stressed conditions, PPE can dramatically reduce their performance by reducing heat transfer and sweat evaporation . This is exemplified in the work undertaken by Carballo‐Leyenda et al They found that PPE led to a low perspiration evaporation rate, which increased the thermophysiological response of wildland firefighters and reduced performance by around 50% …”

Influence of Personal Protective Equipment on Wildland Firefighters’ Physiological Response and Performance during the Pack Test

“…Specifically, it is common to perform the PT dressed in sports clothing (e.g., shorts, T-shirt, running shoes). However, wildland firefighters (WFF) have to wear their personal protective equipment (PPE) (i.e., coveralls, gloves, helmet and boots) during their deployments [ 9 , 10 ]. This fact might affect PT performance since wearing a protective ensemble is heavier (~6 kg) and more restrictive to heat dissipation than exercise clothing [ 11 , 12 ].…”