Physical demands of firefighter search and rescue in ambient environmental conditions.

This study investigated the physiological responses and limitations to a simulated search and rescue scenario in a high-rise building under ambient conditions. Sixteen firefighters performed the scenario under four conditions: standard duration breathing apparatus (SDBA) and 45 mm hose; extended duration breathing apparatus (EDBA) and 45 mm hose; SDBA and 70 mm hose; EDBA and 70 mm hose. Core temperature, skin temperature and heart rate were monitored. In four of 32 trials the casualty was rescued; the remainder of the trials were terminated for safety, high core temperature or shortage of air. Final core temperature and heart rate were higher in the EDBA (39.1 degrees C; 72% heart rate reserve (HRR)) than SDBA conditions (38.6 degrees C; 67%HRR). No differences were observed between hose sizes. The scenario proved too onerous to complete successfully in the majority of cases. Replacing SDBA with EDBA eliminates air supply as a limiting factor, but brings with it challenges of managing thermal strain.