title: Immune and inflammatory responses of Australian firefighters after repeated exposures to the heat.
abstract: When firefighters work in hot conditions, altered immune and inflammatory responses may increase the risk of a cardiac event. The present study aimed to establish the time course of such responses. Forty-two urban firefighters completed a repeat work protocol in a heat chamber (100 ± 5°C). Changes to leukocytes, platelets, TNFα, IL-6, IL-10, LPS and CRP were evaluated immediately post-work and also after 1 and 24 h of rest. Increases in core temperatures were associated with significant increases in leukocytes, platelets and TNFα directly following work. Further, platelets continued to increase at 1 h (+31.2 ± 31.3 × 10(9) l, p < 0.01) and remained elevated at 24 h (+15.9 ± 19.6 × 10(9) l, p < 0.01). Sustained increases in leukocytes and platelets may increase the risk of cardiac events in firefighters when performing repeat work tasks in the heat. This is particularly relevant during multi-day deployments following natural disasters. Practitioner Summary: Firefighters regularly re-enter fire affected buildings or are redeployed to further operational tasks. Should work in the heat lead to sustained immune and inflammatory changes following extended rest periods, incident controllers should plan appropriate work/rest cycles to minimise these changes and any subsequent risks of cardiac events.
authors.affiliation: a UC Research Institute for Sport and Exercise, University of Canberra , Canberra , Australia.|b ACT Fire & Rescue Service , Canberra , Australia.|c Discipline of Sport and Exercise Science, Faculty of Health, University of Canberra, Bruce , ACT 2601, Canberra , Australia.
authors.forename: Anthony
authors.initials: A
authors.lastname: Walker
authors.affiliation: d ACT Ambulance Service , Canberra , Australia.
authors.forename: Toby
authors.initials: T
authors.lastname: Keene
authors.affiliation: a UC Research Institute for Sport and Exercise, University of Canberra , Canberra , Australia.|e ACT Brumbies Super Rugby , Canberra , Australia.
authors.forename: Christos
authors.initials: C
authors.lastname: Argus
authors.affiliation: f Department of Sport and Leisure Studies , University of Waikato , Hamilton , New Zealand.
authors.forename: Matthew
authors.initials: M
authors.lastname: Driller
authors.affiliation: g Department of Sport and Exercise Science , James Cook University , Cairns , Australia.
authors.forename: Joshua H
authors.initials: JH
authors.lastname: Guy
authors.affiliation: a UC Research Institute for Sport and Exercise, University of Canberra , Canberra , Australia.|c Discipline of Sport and Exercise Science, Faculty of Health, University of Canberra, Bruce , ACT 2601, Canberra , Australia.
authors.forename: Ben
authors.initials: B
authors.lastname: Rattray
mesh_terms: D000328:Adult; D001315:Australia; D001831:Body Temperature / Q000276:immunology*; D001835:Body Weight; D002097:C-Reactive Protein / Q000276:immunology; D061388:Firefighters; D006331:Heart Diseases / Q000276:immunology; D006358:Hot Temperature; D006801:Humans; D007249:Inflammation; D016753:Interleukin-10 / Q000276:immunology; D015850:Interleukin-6 / Q000276:immunology; D007958:Leukocyte Count; D008070:Lipopolysaccharides / Q000276:immunology; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure; D010953:Plasma Volume; D010976:Platelet Count; D012146:Rest; D013312:Stress, Physiological / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology; D014940:Work Schedule Tolerance
chemical_list: C508609:IL10 protein, human; C508600:IL6 protein, human; D015850:Interleukin-6; D008070:Lipopolysaccharides; C439524:TNF protein, human; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D002097:C-Reactive Protein
keywords: cardiac risk; immune response; inflammation; occupational stress; safety