Physiological Assessment of Firefighters during a High Rise Scenario

Abstract

1703 In the UK, buildings up to 18 metres high do not have to have firefighting lifts, requiring firefighters to climb stairs before reaching the fire floor. PURPOSE: to assess the physiological demands of a scenario involving simulated Firefighting and Search & Rescue tasks in the dark, in moderate temperatures (∼27°C) on the 5th floor of a high-rise building, under 4 task conditions. METHODS: Sixteen firefighters from London Fire Brigade participated. The four task conditions involved Standard (SDBA) (C1&C3) and Extended Duration Breathing Apparatus (EDBA) (C2&C4), and either 45 (C1&C2) or 70 mm (C3&C4) diameter hose. All participants underwent each condition in teams of two in a randomised fashion. Core temperature, skin temperature, heart rate and air use were monitored throughout; nude mass was measured pre- and post-trial. Mean (sd) age, height and mass of participants were 31.6 ± 4.8 years, 179 ± 5.0 cm and 84.9 ± 8.4 kg. Mean VO2max was 48.0 ± 4.1 ml.kg.−1min−1 and 4.07 ± 0.54 l.min−1. RESULTS: The primary reason for termination in SDBA conditions was shortage of air; and in EDBA conditions was achieving the withdrawal core temperature (39.5°C). Final core temperature reached higher values in EDBA compared to SDBA conditions (p<0.01), as they involved significantly longer work durations. The rise in temperature was also greater under EDBA (p<0.01), though mean rate of rise (0.05°C/min) did not differ. Firefighters in 10 of 32 teams reached 39.5°C, when the trials were terminated; 8 of 10 involved EDBA. The mean rise in skin temperature was 2.7°C and rate of rise 0.1°C/min, with no differences between conditions. Mean %HRR for all conditions was 68–72%, corresponding to a ‘hard’ intensity. In SDBA and EDBA, participants lost ∼0.75 l of sweat in ∼25 min, and 1.02 l in ∼34 min, respectively (p<0.01). The rate of sweat loss (0.03 l/min) was not different. Estimated mean air use in SDBA was 58 l.min−1 and in EDBA of 69 l.min−1. CONCLUSION: SDBA provided inadequate air to achieve the objectives, while EDBA provided ample air which sometimes led to high core temperatures and/or suspected exertional heat stress. Identifying the limiting factors to performance in these tasks will enable methods for extending the performance envelope in comparative safety to be explored. Funded by the Fire Research Division, Office of the Deputy Prime Minister, UK