Physiological responses to design adaptations in firefighting PPC during simulated firefighting tasks.

INTRODUCTION: To ameliorate the effects of steam and chemical ingress during firefighting operations, modern Personal Protective Clothing (PPC) require the presence of a moisture barrier. Little research has been undertaken evaluating the impact of this barrier on physiology of firefighters working in different environments. METHODS: Ten Australian recruit firefighters (5 per group), (mean ±SD age 30.8 ± 5.8 years), undertook one of two 20 minute simulated firefighting tasks separated by a 10 minute recovery period; 1) In a heat chamber set at 120 °C, filled with smoke, firefighters conducted a search and rescue task 2) At ambient temperatures (17 °C), firefighters completed firefighting activities. After the recovery period, the task was repeated. A randomised order crossover design saw participants wearing PPC containing either a moisture barrier (BARR) or no moisture barrier (NBAR). RESULTS: Relative to NBAR (37.7 ± 0.7 °C) BARR showed a moderate increase in core temperatures (38.0 ± 0.5 °C, η² = 0.096) and a small increase in air consumption (NBAR 64.5 ± 8.3 L.min^-1, BARR 66.6 ± 1.9 L.min^-1, η² = 0.037) in the ambient condition group. No meaningful differences for skin temperature or change in body mass were observed. Compared with NBAR (39.0 ± 0.6 °C), BARR resulted in higher skin temperatures (39.6 ± 0.6 °C, η² = 0.178) and greater air consumption (NBAR 45.8 ± 7.5 L.min^-1, BARR 48.7 L.min^-1 ± 7.1, η² = 0.044) and a greater change in body mass (NBAR 2.4 ± 0.6 %, BARR 2.6 ± 0.9 %, η² = 0.021) in the heat chamber. No differences for core temperatures were observed in the heat chamber group. CONCLUSION: The presence of a moisture barrier in structural firefighting PPC may be increasing thermal stress encountered in firefighting settings. Increased strain resulting from design changes may require re-evaluation of work practices to account for the stress of wearing structural PPC when responding to emergencies. (PsycInfo Database Record (c) 2022 APA, all rights reserved)