Cooling vests incorporated with phase change materials (PCMs) add extra insulation and restrict sweat evaporation. It is still unclear how much cooling benefit they can provide. The aim of this study was to investigate the torso cooling of the PCM vests in two hot environments: hot humid (HH, 34°C, 75% relative humidity (RH)) and hot dry (HD, 34°C, 37% RH). A pre-wetted torso fabric skin was used to simulate torso sweating on a thermal manikin. Three cooling vests incorporated with three melting temperatures (Tm) of PCMs were tested (Tm = 21°C, Tm = 24°C and Tm = 28°C). They were worn under a military ensemble (total thermal insulation 1.60 clo; evaporative resistance 0.0516 kPaċm2/W), respectively. In a HH environment all the three cooling vests provided effective torso cooling; in a HD environment the cooling benefit was negative. In both environmental conditions, the evaporative cooling was greatly restricted by the cooling vests. The study indicated that when wearing the protective clothing with the relatively low evaporative resistance and when sweat production was high, the cooling vests were effective in a HH environment, but not in a HD environment.
EpsteinYMoranDS. Thermal comfort and heat stress indices. Ind Health2006; 44: 388–398.
2.
NunneleySA. Heat stress in protective clothing: Interactions among physical and physiological factors. Scand J Work Environ Health1989; 15: 52–57.
3.
BarrDGregsonWReillyT. The thermal ergonomics of firefighting reviewed. Appl Ergon2010; 41: 161–172.
4.
BarwoodMJNewtonPSTiptonMJ. Ventilated vest and tolerance for intermittent exercise in hot, dry conditions with military clothing. Aviat Space Environ Med2009; 80: 353–359.
5.
HolmérI. Protective clothing and heat stress. Ergonomics1995; 38: 166–182.
6.
HolmérIKuklaneKGaoC. Test of firefighters’ turnout gear in hot and humid air exposure. Int J Occup Safety Ergon2006; 12: 297–305.
7.
DormanLEHavenithG. The effects of protective clothing on energy consumption during different activities. Eur J Appl Physiol2009; 105: 463–470.
8.
ISO 7243. Hot environments-estimation of the heat stress on working man, based on the WBGT-index (wet bulb globe temperature), Geneva, International Standards Organization, 2003.
9.
KayacanOKurbakA. Effect of garment design on liquid cooling garments. Textil Res J2010; 80: 1442–1455.
10.
KimDLaBatK. Design process for developing a liquid cooling garment hood. Ergonomics2010; 53: 818–828.
Kuklane K, Holmér I, Ohlsson G, et al. Heat stress in ventilated air tight coverall. In: Werner J and Hexamer M (eds) In: proceedings of the 9th international conference on environmental ergonomics (ICEE), vol. 4, Shaker Verlag, Dortmund, 2000, pp.361-364.
13.
XuXGonzalezJ. Determination of the cooling capacity for body ventilation system. Eur J Appl Physiol2011; 111: 3155–3160.
14.
HadidAYanovichRErlichT. Effect of a personal ambient ventilation system on physiological strain during heat stress wearing a ballistic vest. Eur J Appl Physiol2008; 104: 311–319.
15.
ChinevereTCadaretteBGoodmanD. Efficacy of body ventilation system for reducing strain in warm and hot climates. Eur J Appl Physiol2008; 103: 307–314.
16.
GaoCKuklaneKHolmérI. Cooling vests with phase change materials: The effects of melting temperature on heat strain alleviation in an extremely hot environment. Eur J Appl Physiol2011; 111: 1207–1216.
17.
ArngrímssonSÁPetittDSStueckMG. Cooling vest worn during active warm-up improves 5-km run performance in the heat. J Appl Physiol2004; 96: 1867–1874.
18.
ChouCTochiharaYKimT. Physiological and subjective responses to cooling devices on firefighting protective clothing. Eur J Appl Physiol2008; 104: 369–374.
19.
BennettBLHaganRDHueyKA. Comparison of two cool vests on heat-strain reduction while wearing a firefighting ensemble. Eur J Appl Physiol1995; 70: 322–328.
20.
WebsterJHollandEJSleivertsG. A light-weight cooling vest enhances performance of athletes in the heat. Ergonomics2005; 48: 821–837.
CarterJMRaysonMPWilkinsonDM. Strategies to combat heat strain during and after firefighting. J Therm Biol2007; 32: 109–116.
23.
ChoiJWKimMJLeeJY. Alleviation of heat strain by cooling different body areas during red pepper harvest work at WBGT 33°C. Ind Health2008; 46: 620–628.
24.
GaoCKuklaneKHolmérI. Cooling vests with phase change material packs: the effects of temperature gradient, mass and covering area. Ergonomics2010; 53: 716–723.
25.
BendkowskaWKlonowskaMKopiasK. Thermal manikin evaluation of PCM vests. Fibres Text East Eur2010; 18: 70–74.
26.
LouhevaaraVIlmarinenRGriefahnB. Maximal physical work performance with European standard based fire-protective clothing system and equipment in relation to individual characteristics. Eur J Appl Physiol1995; 71: 223–229.
27.
NishiharaNTanabeSHayamaH. A cooling vest for working comfortably in a moderately hot environment. J Physiol Anthropol Appl Hum Sci2002; 21: 75–82.
28.
ReinertsenREFarevikHHolboK. Optimizing the performance of phase-change materials in personal protective clothing systems. Int J Occup Safety Ergon2008; 14: 43–53.
29.
SmolanderJKuklaneKGavhedD. Effectiveness of a light-weight ice-vest for body cooling while wearing fire fighter’s protective clothing in the heat. Int J Occup Safety Ergon2004; 10: 111–117.
30.
ASTM F2371. Standard test method for measuring the heat removal rate of personal cooling systems using a sweating heated manikin, West Conshohocken, 2010.
31.
Gao C, Kuklane K and Holmér I. Thermoregulatory manikins are desirable for evaluations of intelligent clothing and smart textiles. In: proceedings of the 8th international meeting on thermal manikin and modeling (8I3M), Victoria, Canada, 2010, pp.1–5.
32.
WangFKuklaneKGaoC. Effect of temperature difference between manikin and wet fabric skin surfaces on clothing evaporative resistance: how much error is there?Int J Biometeorol2012; 56: 177–182.
33.
WangFGaoCKuklaneK. Determination of clothing evaporative resistance on a sweating thermal manikin in an isothermal condition: heat loss or mass loss method?Ann Occup Hyg2011; 55: 775–783.
34.
WangFGaoCKuklaneK. A study on evaporative resistances of two skins designed for thermal manikin Tore under different environmental conditions. J Fiber Bioeng Inform (JFBI)2009; 1: 301–305.
35.
CraigFNMoffittJJ. Efficiency of evaporative cooling from wet clothing. J Appl Physiol1974; 36: 313–316.
36.
WangFWangS. Characterization on pore size of honeycomb-patterned micro-porous PET fibers using image processing techniques. Ind Textila2010; 61: 66–69.
