Conference PaperPDF Available


Wenfang Song, Chengjiao Zhang, Fanru Wei, Faming Wang*
Laboratory for Clothing Physiology and Ergonomics (LCPE), Soochow University, China
*Corresponding author: Prof. Faming Wang, email:
An increased number of heat-related illnesses and deaths caused by heatwave episodes (i.e.,
extremely hot environments) have been noted in recent years (1). There is an urgent need to
seek ecologically valid cooling strategies for those populations without access to air-
conditioning during extreme heatwave events. The present study was aimed to examine the
effectiveness of an ecological cooling strategy (i.e., wearing wet clothing) in reducing body
heat strain during a heatwave condition.
Eight healthy male subjects (age: 23.2±2.4 yr; height: 173.0±0.1 cm; body mass: 64.1±4.8 kg)
participated in this study. Each subject underwent two trials, i.e., ordinary summer wear, i.e.,
a short-sleeved polyester shirt, briefs, shorts and sandals (i.e., CON, the intrinsic thermal
insulation of CON was 0.25 clo), and wet clothing (WEC). It was noted that WEC was
achieved by immersing the CON ensemble in water. Subjects were asked to swallow an
ingestible core temperature capsule about 3 h before tests. On arrival for the lab, they sat on a
chair in a room for 30 min (i.e., 23±2 °C, RH=65±5%). Afterwards, they were randomly
assigned in either CON or WEC, entered into a climate chamber (i.e., 43.0±0.5 °C,
RH=57±5% and 0.17±0.05 m/s) and were asked to rest on a chair for 90 min.
Figure 1 presents time course changes in mean skin and core temperatures in CON and WEC.
Mean skin temperature was found to be significantly lower in WEC compared with CON
from the 5th min to the end of the test (p<0.05), and the core temperate was significantly
lower in WEC from the 25th min to the end of the test (p<0.05). The cooling benefit of WEC
may be attributed to the promoted moisture evaporation on WEC that absorbed body heat.
Figure 1. Time course changes in the mean skin and core temperatures in CON and WEC.
1. Kenney W.L., Craighead D.H., Alexander L.M., (2014) Heat waves, aging, and human cardiovascular
health, Medicine & Science in Sports & Exercise, 46(10): 1891-1899.
2. Song W.,Wang F., (2015) The hybrid personal cooling system (PCS) could effectively reduce the heat
strain while exercising in a hot and moderate humid environment, Ergonomics,
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Full-text available
This study aimed to examine the effectiveness of a hybrid personal cooling system (PCS) in mitigating body heat stain while exercising in a hot environment. Eight subjects underwent two trials: PCS and CON (i.e., no cooling). All trials were conducted at an air temperature of 36±0.5 °C and RH=59±5%. The key findings demonstrated that the PCS could significantly reduce the core temperature, mean skin temperature, heart rate and physiological strain index during both exercise and recovery periods (p<0.05). Subjective perceptions were also significantly alleviated in PCS at the end of the exercise and during the recovery (p<0.05). Besides, the PCS could also bring remarkable benefits in lowering local skin temperatures and in improving perceptual sensations in both upper and lower body during both exercise and recovery periods (p<0.05). It was thus concluded that the hybrid PCS is effective in mitigating body heat strain while exercising in a hot environment.
This brief review is based on a President's Lecture presented at the Annual Meeting of the American College of Sports Medicine in 2013. The purpose of this review is to assess the effects of climate change and consequent increases in environmental heat stress on the aging cardiovascular system. The earth's average global temperature is slowly but consistently increasing, and along with mean temperature changes come increases in heat wave frequency and severity. Extreme passive thermal stress resulting from prolonged elevations in ambient temperature, as well as prolonged physical activity in hot environments, creates a high demand on the left ventricle to pump blood to the skin to dissipate heat. Even healthy aging is accompanied by altered cardiovascular function, which limits the extent to which older individuals can maintain stroke volume, increase cardiac output, and increase skin blood flow when exposed to environmental extremes. In the elderly, the increased cardiovascular demand during heat waves is often fatal due to increased strain on an already compromised left ventricle. Not surprisingly, excess deaths during heat waves 1) occur predominantly in older individuals and 2) are overwhelmingly cardiovascular in origin. Increasing frequency and severity of heat waves coupled with a rapidly growing at-risk population dramatically increases the extent of future untoward health outcomes.