The impact of rapid heat stress on firefighters’ dynamic balance

Purpose The study investigated the impact of rate of heating on firefighters’ dynamic balance. Materials and Methods A randomized crossover design was used. All participants completed three visits (baseline, gradual heat stress (NOGEAR), and rapid heat stress (GEAR). Participants performed baseline measures at room temperature during visit one, then walked on a treadmill inside a heat tent in hot, humid conditions (37°C, 50% humidity) either wearing exercise clothing (NOGEAR) or firefighting gear (GEAR) for visits two and three. Participants performed the Y-Balance Test (YBT) and Firefighter Specific Functional Balance Test (FFSFBT) following the heat stress. Results Twenty-three participants (22 male, 1 female; age 34.0 [9.5]; BMI 28.6 [3.4]; years’ experience 11.7 [8.0]) completed this study. Significant increases in all YBT directions were found following the NOGEAR condition. No changes were seen in FFSFBT performance index, though both heat conditions increased FFSFBT errors. Conclusions Increased errors on the FFSFBT may result from impaired risk assessment or cognitive overload during times of high core temperature. Unlike other populations, heat stress in firefighters does not seem to impair the YBT as a metric of dynamic balance. Therefore, one contributing factor to firefighter injuries may be related to cognitive processing rather than physical performance.