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. 2015;21(4):285-93.
doi: 10.1179/2049396715Y.0000000006. Epub 2015 Apr 7.

Repeat work bouts increase thermal strain for Australian firefighters working in the heat

Anthony Walker  1 , Christos Argus, Matthew Driller, Ben Rattray
Affiliations

Repeat work bouts increase thermal strain for Australian firefighters working in the heat

Anthony Walker et al. Int J Occup Environ Health. 2015.

Abstract

Background: Firefighters regularly re-enter fire scenes during long duration emergency events with limited rest between work bouts. It is unclear whether this practice is impacting on the safety of firefighters.

Objectives: To evaluate the effects of multiple work bouts on firefighter physiology, strength, and cognitive performance when working in the heat.

Methods: Seventy-seven urban firefighters completed two 20-minute simulated search and rescue tasks in a heat chamber (105 ± 5°C), separated by a 10-minute passive recovery. Core and skin temperature, rate of perceived exertion (RPE), thermal sensation (TS), grip strength, and cognitive changes between simulations were evaluated.

Results: Significant increases in core temperature and perceptual responses along with declines in strength were observed following the second simulation. No differences for other measures were observed.

Conclusions: A significant increase in thermal strain was observed when firefighters re-entered a hot working environment. We recommend that longer recovery periods or active cooling methods be employed prior to re-entry.

Keywords: Core temperature; Firefighter safety; Heat stress; Perception of effort; Physiology; Recovery.

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Figures

Figure 1
Figure 1
Internal floor plan of heated cell. The cache of drums was located at the top right of the building and entry and exit occurred via the door in the top left. All internal doors were closed during the simulated search and rescue task, and searching was conducted in smoke and darkness
Figure 2
Figure 2
Mean ± SD core temperatures (A), skin temperatures (B), and heart rates (C) of participants during two simulated search and rescue tasks separated by a 10-minute passive rest period. Data were collected at 5-minute intervals after an initial 10-minute search was conducted. * Represents significance at P < 0.05 and ** P < 0.01.
Figure 3
Figure 3
Thermal sensation (TS) (A) and rate of perceived exertion (RPE) (B) of participants during two simulated search and rescue tasks taken at 5-minute time points after an initial 10-minute search was conducted. A 10-minute passive recovery was undertaken between search and rescue tasks. * Represents significance at P < 0.05 and ** P < 0.01.
Figure 4
Figure 4
Results of cognitive testing including speed of processing (A), visual attention (B), and working memory (C). * Represents a significant difference (P < 0.01) between scores pre- to post-simulated search and rescue task. Thermal sensation
See this image and copyright information in PMC

References

    1. Barr D, Gregson W, Reilly T. The thermal ergonomics of firefighting reviewed. Appl Ergon. 2010;41(1):161–72. - PubMed
    1. Eglin CM. Physiological responses to fire-fighting: thermal and metabolic considerations. JHES. 2007;10(1):7–18.
    1. Cheung S, Petersen S, McLellan T. Physiological strain and countermeasures with firefighting. Scand J Med Sci Sports. 2010;20(s3):103–16. - PubMed
    1. McLellan TM, Cheung SS. Impact of fluid replacement on heat storage while wearing protective clothing. Ergonomics. 2020;43(12)–30. - PubMed
    1. Walker A, Driller M, Brearley M, Argus C, Rattray B. Cold water immersion and iced-slush ingestion are effective at cooling firefighters following a simulated search and rescue task in a hot environment. Appl Physiol Nutr Metab. 2014;39(10):1159–66. - PubMed

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