Effects of Fire Fighting Gear on Physiological and Perceptual Responses to Short-Term Fire Fighting Activity

Abstract

Firefighters (FF) routinely perform arduous work in extreme environmental temperatures, thus they require protective clothing. However, the weight and encapsulating nature of the clothing can add to the thermal and cardiovascular strain of a firefighter. PURPOSE: The purpose of this study was to examine the effect of fire fighting gear on the physiological and perceptual responses to an acute bout of fire fighting activity. METHODS: Male FF (N=50) between the ages of 18-50 yrs who were free of known cardiovascular disease participated in 18 minutes of simulated fire fighting activity (stair climbing, forcible entry, searching, advancing a line) in a training structure that contained live fires. Participants were assigned to one of two gear ensembles: standard (n=25) or enhanced (n=25), both of which meet NFPA 1971 standards. The standard gear (avg. wt. 11 kg) consisted of bunker gear with a spun Nomex® lining, a Kevlar fully-encapsulating hood, leather gloves, rubber boots and a traditional-style helmet. The enhanced gear (avg. wt. 8.6 kg) consisted of bunker gear with an Indura FR cotton lining, which circulated exhaled air from the firefighter to the coat's inner lining, a Nomex® hood, a low-profile helmet, leather gloves, and lightweight leather boots. Physiological and perceptual measures were obtained immediately before and after fire fighting activities. RESULTS: There was no significant difference between the descriptive measures (age, ht, wt, BMI) of fire fighters assigned to the two gear ensembles. Performing fire fighting activity resulted in significant increases in HR (~80 b·min-1), Tco (~1.2oC), and Tskin-arm (~5.1oC), but there were no significant differences between the increases observed in the two gear ensembles. Perceptions of temperature (using a thermal sensations scale) and respiration (using a respiratory distress scale) increased significantly as a result of fire fighting activity, but there was no difference between post firefighting values, nor were there any differences in RPE post firefighting, as a function of gear ensemble. CONCLUSION: Fire fighting resulted in significant physiological and perceptual changes; however, the effects of the gear ensemble were small compared to the effects of the fire fighting activity itself. This study was supported by DHS AFG EMW-2006-FP-02459