The effect of acclimation and habituation to wearing an Explosives Ordnance Disposal (EOD) suit on heat strain in moderate and hot conditions

  • Michael Zurawlew

    Student thesis: Master's ThesisMaster of Science by Research


    Purpose: The aim of the study was to evaluate the impact of acclimation / habituation on thermal, metabolic and perceptual responses to conducting bomb disposal related activity with and without wearing an Explosive Ordnance Disposal (EOD) suit in a moderate (20°) and a hot (40°C) environment.

    Methods: With ethical approval from Coventry University Ethics Committee 5 male and 1 female non heat acclimated participants completed the investigation. Four experimental trials were conducted over an 8 day period both before and after an acclimation / habituation period (6 acclimation / habituation sessions whilst wearing the EOD suit for 60 min treadmill walking at 4 km·hr-1 in 21.6±1.2°C, 47.0±5.4% RH completed over 9 days; 2 days on 1 day off pattern; the internal fan system was switched off throughout). Within each experimental trial participants completed a 66 min EOD related activity sequence (Thake and Price 2007) that was modified to standardise work rate. In the first and third trials basic military clothing was worn (no suit trials; NS) and the EOD bomb disposal suit, with its internal fan system switched on, was worn in the second and fourth trials (EOD trials). Ambient temperature (20° or 40°C) was applied to these trials using a cross-over type design. 
    Results: Acclimation / habituation reduced (P<0.05) TC (°C), heat storage, HR, O2, E, physiological strain, RPE, thermal sensation, thermal comfort and perceptual strain when the EOD suit was worn in both 20° and 40°C trials compared to PRE acclimation / habituation measurements. No change in mean sweat rate was induced and TSK was not reduced in 40°C but declined (P<0.001) in 20°C. The magnitude of reduction was greatest in the 20°C EOD versus 40°C EOD. All participants completed PRE and POST 20°C EOD trials and tolerance increased from 53:48±11.59 (min:sec) to 60:10±09:34 (min:sec) in 40°C EOD following acclimation / habituation. Acclimation / habituation also reduced (P<0.05) TC, HR, O2, thermal sensation, thermal comfort and perceptual strain in 20°C and 40°C NS trials. Again no change in mean sweat rate was induced by acclimation / habituation in either NS trials. However lower TSK, physiological strain and RPE values were noted in 20°C NS POST trials and lower heat storage and E values were found in 40°C NS POST trials compared to PRE acclimation / habituation measurements. 
    Conclusion: Six one hour acclimation / habituation sessions of wearing the EOD suit whilst walking at 4 kmhr-1 at an ambient temperature of 21.6±1.2°C, 47.0±5.4% RH induced beneficial thermal, metabolic and perceptual changes that are evident when conducting EOD related activities in both temperate and hot conditions. Such adaptations are likely to be associated with improved work capacity and an improved ability to maintain operational effectiveness.
    Date of Award2009
    Original languageEnglish
    Awarding Institution
    • Coventry University
    SponsorsNP Aerospace Ltd
    SupervisorDoug Thake (Supervisor)


    • applied physiology
    • thermal strain
    • exercise physiology
    • bomb disposals
    • explosive ordnance disposal suit
    • heat acclimation

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