Physiological response to firefighting activities of various work cycles using extended duration and prototype SCBA

Area of Science:

• Occupational Health
• Physiology
• Firefighting Safety

Background:

• Firefighters' self-contained breathing apparatus (SCBA) is crucial for respiratory protection but adds physiological stress.
• Extended duration SCBA (>30 minutes) may prolong work cycles, impacting firefighter performance and safety.

Purpose of the Study:

• To investigate the physiological effects of different SCBA configurations and work/rest cycle variations on firefighters.
• To assess how SCBA use and work cycle design influence physiological responses and work output during simulated firefighting.

Main Methods:

• Thirty firefighters performed seven trials involving simulated firefighting bouts with varying SCBA types and work/rest durations.
• Physiological parameters including heart rate, core temperature, and oxygen consumption were monitored, alongside work output and subjective perceptions.

Main Results:

• SCBA cylinder size had minor effects on measured physiological parameters.
• A second bout of work significantly decreased work output and elevated heart rate and core temperature compared to a single bout.
• 37% of participants failed to complete the second bout in two-bout conditions, with lower fitness and higher body mass correlating with this inability.

Conclusions:

• Extended work cycles without rest periods impose significant physiological strain on firefighters, leading to reduced work capacity.
• Firefighter fitness level is a critical factor in their ability to withstand prolonged work demands, particularly when using SCBA.