Perspired moisture plays a crucial role in the thermal physiology and protection of the human body wearing thermal protective clothing. Until now, the role of continuous sweating on heat transfer, when simultaneously considering internal and external heat sources, has not been well-investigated. To bridge this gap, a sweating torso manikin with 12 thermal protective fabric systems and a radiant heat panel were applied to mimic firefighting. The results demonstrated how the effect of radiant heat on heat dissipation interacted with amount of perspired moisture and material properties. A dual effect of perspired moisture was demonstrated. For hydrophilic materials, sweating induced evaporative cooling but also increased radiant heat gain. For hydrophilic station uniforms, the increment of radiant heat gain due to perspired moisture was about 11% of the increase of heat dissipation. On the other hand, perspired moisture can increase evaporative cooling and decrease radiant heat gain for hydrophobic materials. In addition to fabric thermal resistance (Rct) and evaporative resistance (Ret), material hydrophilicity and hydrophobicity, emissivity and thickness are important when assessing metabolic heat dissipation and radiant heat gain with profuse sweating under radiant heat. The results provide experimental evidence that Rct and Ret, the general indicators of the clothing thermo-physiological effect, have limitations in characterizing thermal comfort and heat strain during active liquid sweating in radiant heat. This paper offers a more complete insight into clothing thermal characteristics and human thermal behaviors under radiant heat, contributing to the accurate evaluation of thermal stress for occupational and general individuals.
Pan N. Sweat management for military applications. In: Wilusz E (ed.) Military textiles. Cambridge: Woodhead Publishing, 2008, pp.137–157.
2.
RossiR. Fire fighting and its influence on the body. Ergonomics2003; 46: 1017–1033.
3.
ISO 11092:2014. Textiles — physiological effects — measurement of thermal and water-vapour resistance under steady-state conditions (sweating guarded-hotplate test).
4.
BrödePKuklaneKCandasV, et al.Heat gain from thermal radiation through protective clothing with different insulation, reflectivity and vapour permeability. Int J Occup Saf Ergon2010; 16: 231–244.
5.
DenHartogEAWalkerMABarkerRL. Total heat loss as a predictor of physiological response in wildland firefighter gear. Text Res J2015; 86: 710–726.
6.
FuMWengW-GYuanH-Y. Combined effects of moisture and radiation on thermal performance of protective clothing: experiments by a sweating manikin exposed to low level radiation. Int J Cloth Sci Tech2015; 27: 818–834.
7.
SongG-WStephenPRohitS, et al.Thermal protective performance of protective clothing used for low radiant heat protection. Text Res J2010; 81: 311–323.
8.
SunGYooHSZhangXS, et al.Radiant protective and transport properties of fabrics used by wildland firefighters. Text Res J2016; 70: 567–573.
9.
Song G-W, Mandal S and Rossi RM. Performance evaluation of thermal protective clothing. Thermal protective clothing for firefighters. Cambridge: Woodhead Publishing, 2017, pp.57–144.
10.
ASTM F1868:2017. Standard test method for thermal and evaporative resistance of clothing materials using a sweating hot plate.
11.
HuangJ-H. Review of heat and water vapor transfer through multilayer fabrics. Text Res J2015; 86: 325–336.
12.
HuangJ-H. Sweating guarded hot plate test method. Polym Test2006; 25: 709–716.
13.
ASTM F2370:2016. Standard test method for measuring the evaporative resistance of clothing using a sweating manikin.
14.
ASTM F1291:2016. Standard test method for measuring the thermal insulation of clothing using a heated manikin.
15.
ISO 9920:2007. Ergonomics of the thermal environment -estimation of thermal insulation and water vapour resistance of a clothing ensemble.
16.
KothariVKChakrabortyS. Thermal protective performance of clothing exposed to radiant heat. J Text I2015; 106: 1388–1393.
17.
MandalSSongGAckermanM, et al.Characterization of textile fabrics under various thermal exposures. Text Res J2012; 83: 1005–1019.
18.
ZhuF-LZhangW-YSongG-W. Heat transfer in a cylinder sheathed by flame-resistant fabrics exposed to convective and radiant heat flux. Fire Saf J2008; 43: 401–409.
19.
MandalSSongG. An empirical analysis of thermal protective performance of fabrics used in protective clothing. Ann Occup Hyg2014; 58: 1065–1077.
20.
BarkerRLDeatonASRossKA. Heat transmission and thermal energy storage in firefighter turnout suit materials. Fire Technol2010; 47: 549–563.
21.
BarkerRLGuerth-SchacherCGrimesRV, et al.Effects of moisture on the thermal protective performance of firefighter protective clothing in low-level radiant heat exposures. Text Res J2006; 76: 27–31.
22.
FuMWengW-GYuanH-Y. Quantitative investigation of air gaps entrapped in multilayer thermal protective clothing in low-level radiation at the moisture condition. Fire Mater.2016; 40(2): 179–89.
23.
FuMWengW-GYuanH-Y. Quantitative assessment of the relationship between radiant heat exposure and protective performance of multilayer thermal protective clothing during dry and wet conditions. J Hazard Mater2014; 276: 383–392.
24.
SongG-WCaoWFarzanG. Analyzing stored thermal energy and thermal protective performance of clothing. Text Res J2011; 81: 1124–1138.
25.
KeiserCRossiRM. Temperature analysis for the prediction of steam formation and transfer in multilayer thermal protective clothing at low level thermal radiation. Text Res J2008; 78: 1025–1035.
26.
LeeYMBarkerRL. Effect of moisture on the thermal protective performance of heat-resistant fabrics. J Fire Sci1986; 4: 315–331.
27.
LawsonLKCrownEMAckermanMY, et al.Moisture effects in heat transfer through clothing systems for wildland firefighters. Int J Occup Saf Ergon2004; 10: 227–238.
28.
LiX-HLuY-HLiJ, et al.A new approach to evaluate the effect of moisture on heat transfer of thermal protective clothing under flashover. Fiber Polym2012; 13: 549–554.
29.
WangY-YLuY-HLiJ, et al.Effects of air gap entrapped in multilayer fabrics and moisture on thermal protective performance. Fiber Polym2012; 13: 647–652.
30.
Rossi RM and Zimmerli T. Influence of humidity on the radiant, convective and contact heat transmission through protective clothing materials. In: Johnson J and Mansdorf S (eds) Performance of protective clothing: fifth volume. West Conshohocken, PA: ASTM International, 1996, pp.269–280.
31.
Stull JO. Comparative thermal insulative performance of reinforced knee areas of firefighter protective clothing. In: Performance of protective clothing: issues and priorities for the 21st century: seventh volume. West Conshohocken, PA: ASTM International, 2000, pp.312–328.
32.
Mäkinen H, Smolander J and Vuorinen H. Simulation of the effect of moisture content in underwear and on the skin surface on steam burns of fire fighters. In: S Mansdorf, R Sager and A Neilsen (eds.) performance of protective clothing: second symposium, Tampa, FI, 19 January-21 January 1987, paper no. STP989-EB, pp. 415–421. Philadelphia, PA: ASTM International. 1988.
33.
ISO 7933:2004. Ergonomics of the thermal environment – analytical determination and interpretation of heat stress using calculation of the predicted heat strain.
34.
Den HartogEAHavenithG. Analytical study of the heat loss attenuation by clothing on thermal manikins under radiative heat loads. Int J Occup Saf Ergon2010; 16: 245–261.
35.
ISO3801:1977. Textiles – woven fabrics – determination of mass per unit length and mass per unit area.
36.
ISO5084:1996. Textiles – determination of thickness of textiles and textile products.
37.
ISO18640-1:2018. Protective clothing for firefighters — physiological impact — Part 1: measurement of coupled heat and moisture transfer with the sweating torso.
38.
ISO18640-2:2018. Protective clothing for firefighters — physiological impact — Part 2: determination of physiological heat load caused by protective clothing worn by firefighters.
39.
AnnaheimSWangL-CPsikutaA, et al.A new method to assess the influence of textiles properties on human thermophysiology. Part I. Int J Cloth Sci Tech2015; 27: 272–282.
40.
Zimmerli T and Weder MS. Protection and comfort—a sweating torso for the simultaneous measurement of protective and comfort properties of PPE. Performance of protective clothing: sixth volume. West Conshohocken, PA: ASTM International, 1997, pp.271–280.
41.
Wang F-M, Havenith G, Mayor TS, et al. (eds). Clothing real evaporative resistance determined by means of a sweating thermal manikin: a new round-robin study. In: M Varheenmaa (ed.) 10th manikin and modelling meeting (10i3m), Tampere, Finland, 7–9 September 2014, paper no. 145. Tampere, Finland: Tampere University of Technology. Department of Materials Science.
42.
Song G-W, Mandal S and Rossi RM. Modeling and its implications on performance of thermal protective clothing. Thermal protective clothing for firefighters. Cambridge: Woodhead Publishing, 2017, pp.145–161.
43.
ANSI/ASHRAE Standard 55, Thermal environmental conditions for human occupancy. 2004.
44.
KwonAKatoMKawamuraH, et al.Physiological significance of hydrophilic and hydrophobic textile materials during intermittent exercise in humans under the influence of warm ambient temperature with and without wind. Eur J Appl Physiol Occup Physiol1998; 78: 487–493.
45.
MertEPsikutaABuenoMA, et al.The effect of body postures on the distribution of air gap thickness and contact area. Int J Biometeorol2017; 61: 363–375.
46.
HuJ-YLiYYeungK-W, et al.Moisture management tester: a method to characterize fabric liquid moisture management properties. Text Res J2016; 75: 57–62.
47.
Frackiewicz-KaczmarekJPsikutaABuenoM-A, et al.Effect of garment properties on air gap thickness and the contact area distribution. Text Res J2015; 85: 1907–1918.
48.
Frackiewicz-KaczmarekJPsikutaABuenoM-A, et al.Air gap thickness and contact area in undershirts with various moisture contents: influence of garment fit, fabric structure and fiber composition. Text Res J2015; 85: 2196–2207.
49.
MertEPsikutaABuenoM-A, et al.Effect of heterogenous and homogenous air gaps on dry heat loss through the garment. Int J Biometeorol2015; 59: 1701–1710.
