Physiological Strain Among Fire Fighters Performing Non-Fire Emergency Services

PURPOSE: Firefighters (FFs) often perform other services outside of what is traditionally thought of as firefighting (i.e., fire suppression), for example, they provide non-fire emergency services for large-scale local events. Despite appearing to be less physically demanding than fire-related duties, it is unclear whether FFs experience heightened levels of physiological strain while providing non-fire emergency services. METHODS: 15 male FFs (M ± SD; age = 40 ± 11 y, 100% white/Caucasian) were observed across 5 games while performing emergency medical services during home football games at The University of Alabama. FFs completed health and exercise history questionnaires; heart rate (HR), blood pressure (BP), and body weight were measured pre- and post-shift. FFs were assigned to a bike (n = 6) or logistics (n = 9) team and wore GPS-enabled monitoring systems that recorded physiological and environmental data during each shift. Analyses included descriptive statistics, independent t-tests, and bivariate correlations. RESULTS: Averaged across the 5 games, shifts lasted 8.2 ± 1.0 h and reached temperatures of 22.8 ± 3.0 °C. FFs were obese (based on body mass index [BMI] = 33.1 ± 6.2 kg/m2) and had stage 2 hypertension based on pre-shift resting systolic BP/diastolic BP values (142.6 ± 14.2/85.7 ± 29.2 mmHg). FFs assigned to the bike team were younger (MD ± SD; -13.8 ± 16.6 y, p < 0.001), had a lower BMI (-5.1 ± 9.2 kg/m2, p = 0.02), but achieved higher average HR (8.1% ± 11.5% of maximal HR, p = 0.002) and training intensity (a measure of combined mechanical and cardiac load: 0.5 ± 0.5 units, p < 0.001) compared to logistics. Average HR (r = 0.69, p < 0.001), peak core temperature (r = 0.57, p = 0.003), and distance traveled (r = 0.77, p = 0.01) were positively associated with a higher training intensity. Age (r = -0.74, p < =0.001) and BMI (r = -0.53, p = 0.02) were negatively associated with training intensity. CONCLUSIONS: FFs presented with suboptimal cardiovascular health and experienced increased levels of physiological strain while performing non-fire emergency services. Physiological strain differed by FF assignment (bike vs. logistics), but it also appeared to be mediated by individual factors. Improving cardiovascular health should remain a top priority for the health, safety, and performance of FFs.