title: Inside the 'Hurt Locker': The Combined Effects of Explosive Ordnance Disposal and Chemical Protective Clothing on Physiological Tolerance Time in Extreme Environments.
abstract: BACKGROUND
  Explosive ordnance disposal (EOD) technicians are often required to wear specialized clothing combinations that not only protect against the risk of explosion but also potential chemical contamination. This heavy (>35kg) and encapsulating ensemble is likely to increase physiological strain by increasing metabolic heat production and impairing heat dissipation. This study investigated the physiological tolerance times of two different chemical protective undergarments, commonly worn with EOD personal protective clothing, in a range of simulated environmental extremes and work intensities
  
  
  METHODS
  Seven males performed 18 trials wearing 2 ensembles. The trials involved walking on a treadmill at 2.5, 4, and 5.5 km h(-1) at each of the following environmental conditions, 21, 30, and 37°C wet bulb globe temperature. The trials were ceased if the participants' core temperature reached 39°C, if heart rate exceeded 90% of maximum, if walking time reached 60min or due to volitional fatigue.
  
  
  RESULTS
  Physiological tolerance times ranged from 8 to 60min and the duration (mean difference: 2.78min, P > 0.05) were similar in both ensembles. A significant effect for environment (21 > 30 > 37°C wet bulb globe temperature, P < 0.05) and work intensity (2.5 > 4 > 5.5 km h(-1), P < 0.05) was observed in tolerance time. The majority of trials across both ensembles (101/126; 80.1%) were terminated due to participants achieving a heart rate equivalent to greater than 90% of their maximum.
  
  
  CONCLUSIONS
  Physiological tolerance times wearing these two chemical protective undergarments, worn underneath EOD personal protective clothing, were similar and predominantly limited by cardiovascular strain.
authors: 1.Extreme Environments Laboratory (EEL), Department of Sport and Exercise Science, Spinnaker Building, Cambridge Road, University of Portsmouth, Portsmouth, PO1 2ER, UK 2.School of Exercise and Nutrition Sciences and Institute of Health and Biomedical Innovation, Kelvin Grove, Queensland University of Technology, Brisbane, Queensland 4059, Australia joe.costello@port.ac.uk.
authors: Joseph T
authors: JT
authors: Costello
authors: 2.School of Exercise and Nutrition Sciences and Institute of Health and Biomedical Innovation, Kelvin Grove, Queensland University of Technology, Brisbane, Queensland 4059, Australia.
authors: Kelly L
authors: KL
authors: Stewart
authors: 2.School of Exercise and Nutrition Sciences and Institute of Health and Biomedical Innovation, Kelvin Grove, Queensland University of Technology, Brisbane, Queensland 4059, Australia.
authors: Ian B
authors: IB
authors: Stewart
mesh_terms: D000328:Adult; D001833:Body Temperature Regulation / Q000502:physiology*; D004777:Environment; D005221:Fatigue / Q000209:etiology; D006339:Heart Rate / Q000502:physiology; D006358:Hot Temperature / Q000009:adverse effects; D006801:Humans; D008297:Male; D016273:Occupational Exposure; D005082:Physical Exertion / Q000502:physiology*; D011481:Protective Clothing / Q000009:adverse effects*; D011482:Protective Devices; D055815:Young Adult
keywords: core temperature; heat strain; military; personal protective equipment; thermoregulation; uncompensable heat stress