The Relationship Between Working Conditions and Indices of Stress and Cognitive Function in Wildland Firefighters

Abstract

This study examined the relationship between working conditions and variables related to stress and cognitive function. A within-subject, observation study was conducted on 24 Wildland firefighters (9 F) across British Columbia between July to September of 2021 and 2022. A subset of participants (n=15) measured heart rate variability (HRV) using a chest-worn heart monitor. Perceived stress was measured on a 4-point scale. Cognitive function was measured subjectively, via 7-point scales, and objectively, via the psychomotor vigilance task (PVT). Working conditions were measured post-shift, including whether they conducted wildfire suppression that day (Y/N), were exposed to smoke (Y/N), and fire stage of control on a 4-point scale (i.e., out of control; being held; under control; other). Pearson correlation analyses were performed to identify the largest associates between variables. Stage of control had the greatest number of significant correlations to cognitive function, including subjective fatigue (r = 0.28, p < 0.001) and mean reaction time (RT) (r = 0.34, p < 0.001). The largest associates of both smoke exposure and wildfire suppression were cognitive function variables; subjective fatigue and median RT (Table 1). Indices of stress and cognitive function were significantly correlated to certain working conditions, thus warranting further investigation.