Subjective perceptions and ergonomics evaluation of a liquid cooled garment worn under protective ensemble during an intermittent treadmill exercise

Abstract

While a personal protective equipment (PPE) ensemble effectively provides workers with protection from occupational hazards, working in a vapour-resistant ensemble increases the risk of heat illness/injuries and physiological burdens. The purpose of this study was to investigate the effect of body cooling via a liquid-cooled garment (LCG) underneath a PPE ensemble on perceived thermal strain, physiological responses and ergonomics during an intermittent treadmill exercise in warm environmental conditions. The results of the present study indicated that the concomitant wearing of LCG underneath the PPE ensemble significantly reduced subjective perception of heat and alleviated overall increase in body temperature and heart rate while no impact of wearing LCG on ergonomic features was found. The extension of the present findings to practical applications in occupational settings requires further research on a LCG system design and performance evaluations while the LCG is incorporated within the PPE ensemble. STATEMENT OF RELEVANCE: Implementation of a LCG underneath PPE for body cooling was investigated, focusing on its impact on individuals' perceived thermal strain, physiological responses and ergonomics. The findings of the present study indicated that body cooling via a wearable LCG underneath PPE significantly alleviated both perceived thermal and physiological strain in uncompensable heat stress condition.

Meta-analysis of the effects of microclimate cooling systems on human performance under thermal stressful environments: Potential applications to occupational workers

“…When the major pathway for heat dissipation is sweat evaporation in a hot environment with a certain level of humidity and air and body motion, the external force with increasing air flow across the body is beneficial for accelerating sweat evaporation and convective heat loss, resulting in the reduction of heat strain and the enhancement of human performance (Oğulata, 2007;Brotherhood, 2008). By circulating cooled liquid on the skin surface, LCGs are well accepted as an effective cooling technique contributing to lower heat strain and better human performance (Teunissen et al, 2014;Kim et al, 2011aKim et al, , 2011b. Unlike active and passive cooling systems, HBCGs have been the focus of less research attention in past, resulting in only two publications included in this study.…”

“…Consequently, 33 scenarios of environmental conditions were identified with air temperature ranging from 30°C to 48°C and relative humidity between 8.6% and 75%. Meanwhile, a total number of 35 cooling agents were investigated, whereas 4 studies used several cooling agents (Vallerand et al, 1991;McLellan et al, 1998;Kaufman and Fatkin, 2001;Kim et al, 2011aKim et al, , 2011b. Classified using the termination criteria of the exercise, the numbers of the types of exercise protocols were n ¼ 26 for time-fixed trials and n ¼ 4 for open-end tests.…”

Body regional influences of l-menthol application on the alleviation of heat strain while wearing firefighter’s protective clothing

“…To date, the following cooling strategies have been suggested as practical countermeasures for reducing heat strain: (1) hand and forearm immersion (Giesbrecht et al 2007;Selkirk et al 2004) (2) cooling garments (Barr et al 2010;Chou et al 2008;Kim et al 2011) (3) air or mister fanning ) (4) altering clothing configuration , and (5) cold drinks consumption (Lee et al 2008a). However, the practical use of these cooling strategies is often limited due to logistical difficulties.…”

Towards Optimizing a Personal Cooling Garment for Hot and Humid Deep Mining Conditions

“…Studies conducted on firefighters concluded that using a liquid-cooled garment under their personal protective equipment improves performance time and helps the body recover within a shorter period of rest [21] [22]. However, with LCGs, there is a risk of skin burn caused by the stream formation that may appear if the water was circulated in the space between the skin and the personal protective equipment [25].…”