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. 2023 Feb 22:14:1122504.
doi: 10.3389/fphys.2023.1122504. eCollection 2023.

Effects of wetted inner clothing on thermal strain in young and older males while wearing ventilation garments

Ken Tokizawa  1
Affiliations

Effects of wetted inner clothing on thermal strain in young and older males while wearing ventilation garments

Ken Tokizawa. Front Physiol. .

Abstract

The present study examined the effect of wearing a water-soaked inner t-shirt with a ventilation garment on thermal and cardiovascular strain in eight young (26 ± 4 years) and eight older (67 ± 3 years) men undertaking moderate-intensity work (metabolic rate: 200-230 W m-2) in a hot environment (37°C, 50% RH, 2.8 kPa). While intermittent walking in hot conditions for 60 min, as a control (CON), the subject wore a dry inner t-shirt (long-sleeved) without fanning of a ventilation jacket (single-layered cotton, 0.21 clo). On separate days, under a fanned ventilation jacket, the subject wore a dry inner t-shirt (DRY) or an inner t-shirt soaked with 350 mL of tap water (WET). In the young group, increases in rectal temperature from pre-exercise baseline in the WET trial (0.7°C ± 0.2°C) were lower than in the CON (1.3°C ± 0.3°C) and DRY (1.1°C ± 0.2°C) (both p < 0.05) trials during exercise in hot conditions. In the older group, the increases were also attenuated in WET (0.7°C ± 0.4°C) compared with CON (1.3°C ± 0.4°C) and DRY (1.1°C ± 0.4°C) (both p < 0.05) without differences between age groups. Heart rate and whole-body sweat loss were lowest in the WET, followed by DRY, and then CON conditions in both groups (all p < 0.05). These findings demonstrate that wearing a water-soaked inner t-shirt while using a ventilation garment is an effective and practical cooling strategy to mitigate thermal and cardiovascular strains in young and older individuals during moderate-intensity work in hot conditions.

Keywords: aging; cooling; core temperature; occupational heat strain; sweat loss.

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Conflict of interest statement

The author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

FIGURE 1
FIGURE 1
Rectal (A,C) and mean skin temperature (B,D) responses during three bouts of intermittent exercise (Ex1–3) in hot conditions (37°C, 50% RH) interspersed by three breaks (B1–3) in the young (left) and older (right) groups while wearing a dry inner t-shirt without ventilation garment fanning in the control (CON, open circles), a dry inner t-shirt with ventilation garment fanning (DRY, opened triangles), and a wetted inner t-shirt with ventilation garments fanning (WET, closed triangles). The arrow indicates the start of fanning (DRY) and wetting and fanning (WET). *Significantly different for CON vs. WET trial, p < 0.05. #Significantly different for DRY vs. WET trial, p < 0.05. §Significantly different for CON vs. DRY trial, p < 0.05. †Significantly different for young vs. older in the WET trial, p < 0.05. Data are expressed as the mean ± SD for eight participants.
FIGURE 2
FIGURE 2
Regional sweating rate (SR) responses on the chest (A, E), back (B, F), forearm (C, G), and thigh (D, H) during three bouts of intermittent exercise (Ex1–3) in hot conditions (37°C, 50% RH) interspersed by three breaks (B1–3) in the young (left) and older (right) groups while wearing a dry inner t-shirt without ventilation garment fanning in the control (CON, open circles), a dry inner t-shirt with ventilation garment fanning (DRY, opened triangles), and a wetted inner t-shirt with ventilation garment fanning (WET, closed triangles). The arrow indicates the start of fanning (DRY) and wetting and fanning (WET). *Significantly different for CON vs. WET trial, p < 0.05. #Significantly different for DRY vs. WET trial, p < 0.05. §Significantly different for CON vs. DRY trial, p < 0.05. Data are expressed as the mean ± SD for eight participants.
FIGURE 3
FIGURE 3
Heart rate (HR) responses during three bouts of intermittent exercise (Ex1–3) in hot conditions (37°C, 50% RH) interspersed by three breaks (B1–3) in the young (A) and older (B) groups while wearing a dry inner t-shirt without ventilation garments fanning in the control (CON, open circles), a dry inner t-shirt with ventilation garment fanning (DRY, opened triangles), and a wetted inner t-shirt with ventilation garment fanning (WET, closed triangles). The arrow indicates the start of fanning (DRY) and wetting and fanning (WET). *Significantly different for CON vs. WET trial, p < 0.05. #Significantly different for DRY vs. WET trial, p < 0.05. §Significantly different for CON vs. DRY trial, p < 0.05. Data are expressed as the mean ± SD for eight participants.
FIGURE 4
FIGURE 4
Heat production during three bouts of intermittent exercise (Ex1–3) in hot conditions (37°C, 50% RH) in the young (A) and older (B) groups while wearing a dry inner t-shirt without ventilation garments fanning in the control (CON, open circles), a dry inner t-shirt with ventilation garment fanning (DRY, opened triangles), and a wetted inner t-shirt with ventilation garment fanning (WET, closed triangles). *Significantly different for CON vs. WET trial, p < 0.05. #Significantly different for DRY vs. WET trial, p < 0.05. Data are expressed as the mean ± SD for eight participants.
FIGURE 5
FIGURE 5
Perceptual responses of thermal sensation (A, E), thermal comfort (B, F), thirst (C, G), and fatigue (D, H) during three bouts of intermittent exercise (Ex1–3) in hot conditions (37°C, 50% RH) interspersed by three breaks (B1–3) in the young (left) and older (right) groups while wearing a dry inner t-shirt without ventilation garment fanning in the control (CON, open circles), a dry inner t-shirt with ventilation garment fanning (DRY, opened triangles), and a wetted inner t-shirt with ventilation garments fanning (WET, closed triangles). The arrow indicates the start of fanning (DRY) and wetting and fanning (WET). *Significantly different for CON vs. WET trial, p < 0.05. #Significantly different for DRY vs. WET trial, p < 0.05. §Significantly different for CON vs. DRY trial, p < 0.05. Data are expressed as the mean ± SD for eight participants.
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References

    1. ACGIH (2007). Heat stress and strain: Threshold limit values for physical agents documentation, 1–36.
    1. American College of Sports Medicine (2013). ACSM’s guidelines for exercise testing and prescription. Philadelphia: Lippincott Williams and Wilkins. - PubMed
    1. Bain A. R., Deren T. M., Jay O. (2011). Describing individual variation in local sweating during exercise in a temperate environment. Eur. J. Appl. Physiol. 111, 1599–1607. 10.1007/S00421-010-1788-9 - DOI - PubMed
    1. Barwood M. J., Newton P. S., Tipton M. J. (2009). Ventilated vest and tolerance for intermittent exercise in hot, dry conditions with military clothing. Aviat. Space Environ. Med. 80, 353–359. 10.3357/ASEM.2411.2009 - DOI - PubMed
    1. Bröde P., Havenith G., Wang X., Candas V., den Hartog E. A., Griefahn B., et al. (2007). Non-evaporative effects of a wet mid layer on heat transfer through protective clothing. Eur. J. Appl. Physiology 104, 341–349. 10.1007/S00421-007-0629-Y - DOI - PubMed

Grants and funding

The project research of National Institute of Occupational Safety and Health, Japan.