title: The impact of various rehydration volumes for firefighters wearing protective clothing in warm environments.
abstract: This study examined different fluid replacement quantities during intermittent work while wearing firefighting protective clothing and self-contained breathing apparatus in the heat (35 degrees C, 50% relative humidity). Twelve firefighters walked at 4.5 km per h with 0% elevation on an intermittent work (50 min) and rest (30 min) schedule until they reached a rectal temperature of 39.5 degrees C during work periods and 40.0 degrees C during rest, heart rates of 95% of maximum and/or exhaustion. During the heat-stress trials subjects received one of four fluid replacement quantities, high (H), moderate (M), low (L), and no hydration (NH), where H, M and L represented 78%, 63% and 37% of fluid loss, respectively. The total tolerance time (work + rest) was significantly greater during H (111.8 +/- 3.5), M (112.9 +/- 5.2) and L (104.2 +/- 5.8) compared to NH (95.3 +/- 3.8). In addition, work time (min), which excluded rest periods, was significantly greater in H (82.6 +/- 3.5), and M (82.9 +/- 5.2) compared to NH (65.3 +/- 3.8). It is concluded that incorporating even partial fluid replacement strategies while wearing firefighting protective clothing and self-contained breathing apparatus in the heat improves tolerance time.
authors.affiliation: Operational Medicine Section, Defence R&D Canada--Toronto, 1133 Sheppard Avenue West, P.O. Box 2000, Toronto, Ontario M3M 3B9, Canada.
authors.forename: G A
authors.initials: GA
authors.lastname: Selkirk
authors.forename: T M
authors.initials: TM
authors.lastname: McLellan
authors.forename: J
authors.initials: J
authors.lastname: Wong
mesh_terms: D005390:Fires; D005440:Fluid Therapy; D018882:Heat Stress Disorders / Q000378:metabolism*; D006801:Humans; D008875:Middle Aged; D009864:Ontario; D011481:Protective Clothing; D018635:Rescue Work