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Utilization of Active Cooling in Hot Environments While Wearing Encapsulated Protective Ensembles

Aljaroudi, Ali
http://rave.ohiolink.edu/etdc/view?acc_num=ucin1509983514105392

Abstract Details

2017, PhD, University of Cincinnati, Medicine: Occupational Safety and Ergonomics.
Objective: The objective of this laboratory-based study was to investigate the effect of heat/active continuous cooling on the body’s physiological responses, postural balance/gait stability, and cognitive function responses of subjects wearing firefighters’ encapsulating protective ensembles during exercise in a simulated hot environment. Methods: Twelve healthy physically-fit males were recruited for this cross-sectional study. A maximal graded exercise test was performed before experimental events in order to calculate maximal oxygen uptake and to assess participants’ capacity to perform the assigned exercise. Physiological measures (heart rate, body core temperature, mean skin temperature, body weight), perceptual measures (physical exertion, thermal compensation, and respiratory distress), static balance metrics (sway speed, sway area, excursion along x and y axis), dynamic balance associated with gait outcomes (gait velocity, gait cadence, turn duration, turn peak velocity, range of motion and peak swing velocity of torso, arms and legs), cognitive measures (performance rate errors, reaction times) were obtained before and after exercising inside an environmental chamber. Exercise included treadmill walking while wearing encapsulating firefighters’ protective ensembles at 40 % maximal oxygen capacity in warm (30°C) and humid (70%) environmental conditions for 40 minutes or until body core temperature ˜ 39 °C. Subjects participated in two randomly assigned sessions of the exercise protocol: control (no cooling) and experimental (active cooling application). For experimental sessions, a cooling garment with tubing sewn into the inside surface of the fabric was worn underneath firefighters’ protective ensembles and infused with cooled water (18°C) supplied by an external water circulator. Skin surface areas in contact with the garment for heat exchange included head, torso, forearm, and thigh area. Results: Participants’ physiological responses were significantly increased after exercise in a warm and humid environment. Static balance metrics were significantly increased as well. A significant effect was found in dynamic balance associated with upper extremity swing but not in legs and gait characteristics. Participants’ reaction time was significantly reduced after experiencing thermal strain and reaching the industrial hyperthermia threshold limit (38°C). Hyperthermia exhibited a non-significant effect of hyperthermia in percentage performance error. The cooling method had a significant impact on decreasing the physiological responses but not the static and dynamic balance outcomes or cognitive function. Conclusion: Exercise in a hot and humid environment combined with the wearing encapsulating firefighters’ protective ensembles can result in significant physiological and thermal burden including industrial hyperthermia and high fatigue levels. It can also result in significant alterations in biomechanical motor control represented by static and dynamic balance, but not gait characteristics and lower extremity’s motion. It can also affect the cognitive function as represented by measured change in impulsivity and attention. Utilization of the liquid cooling garment underneath the firefighters’ ensemble significantly reduced physiological and thermal strain, extended hyperthermia survival time, and enhanced the duration of physical activities, however, the proposed cooling method does not appear to have any significant impact on static or dynamic balance and gait. Cognitive function may also not receive any significant benefit from the liquid cooling.
Amit Bhattacharya, Ph.D. (Committee Chair)
William Jetter, Ph.D. (Committee Member)
Darren Kadis (Committee Member)
Ming-Lun Lu, Ph.D. (Committee Member)
Marepalli Rao, Ph.D. (Committee Member)
W. Williams, Ph.D. (Committee Member)
74 p.
Environmental Health
Firefighters; Heat Stress; Liquid Cooling; Physiology; Postural Balance; Cognitive Function

Recommended Citations

Citations

  • Aljaroudi, A. (2017). Utilization of Active Cooling in Hot Environments While Wearing Encapsulated Protective Ensembles [Doctoral dissertation, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1509983514105392

    APA Style (7th edition)

  • Aljaroudi, Ali. Utilization of Active Cooling in Hot Environments While Wearing Encapsulated Protective Ensembles. 2017. University of Cincinnati, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ucin1509983514105392.

    MLA Style (8th edition)

  • Aljaroudi, Ali. "Utilization of Active Cooling in Hot Environments While Wearing Encapsulated Protective Ensembles." Doctoral dissertation, University of Cincinnati, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1509983514105392

    Chicago Manual of Style (17th edition)

ucin1509983514105392
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© 2017, all rights reserved.
This open access ETD is published by University of Cincinnati and OhioLINK.