Showering in winter was a transitional process with a significant rise and drop in temperature as the naked body was exposed to hot water and cold air. It can cause sudden changes in the elderly's thermo-physiology, posing a risk to their physical health due to decreased cardiovascular and thermoregulatory adaptability. To investigate the elderly's thermo-physiological responses to transient temperature during showering in winter, 15 elderly subjects over the age of 60 and 5 younger adults were recruited for a field study at a nursing home in Chongqing. Showering water and bathroom air temperature were monitored. Heart rate, blood pressure and skin temperature were measured using physiological wrist and attached sensors. The variability of thermo-physiological indices was proposed as an indicator to evaluate the effects of transient temperature. The results showed that the temperature difference between water and air ranged from 7.4 to 26.2°C. Every 10°C difference in temperature caused a 10% increase in heart rate, 4% in diastolic blood pressure, and 1% in skin temperature. Thermo-physiological asymmetry between hot and cold stimuli was under 15%. This research can provide references for research on thermo-physiology in transient temperatures and the creation of healthy and intelligent bathroom environments for the elderly.
MatsuiKS. Descriptive epidemiology of accidental drowning in the bathtub (in Japanese). J Health Welf Stat2009; 56: 16–21.
4.
SuzukiMShimboTIkagaT,HoriS.Sudden death phenomenon while bathing in Japan - mortality data. Circ J2017; 81: 1144. –+.
5.
ShiPC. Study on environmental control strategy of residential bathroom based on human thermophysiological changes. Nanjing: Southeast University, Master’s thesis, 2020.
6.
WangTYZhouHSunQH. Fluctuation in ambient temperature: interplay between brown adipose tissue, metabolic health, and cardiovascular diseases. Environ Disease2016; 1: 3. doi:10.4103/2468-5690.180334
7.
HuangQQLiJ. Research progress on the mechanism of human body thermal sensation under abrupt ambient temperature. J Text Sci2020; 41: 188–194.
8.
LuoMHXuSTangYYuHZhouXChenZ.Dynamic thermal responses and showering thermal comfort under different conditions. Build Environ2023; 237: 110322.
9.
HashiguchiNNiFTochiharaY. Effects of room temperature on physiological and subjective responses to bathing in the elderly. J Hum-Environ Sys2012; 15: 13–19. doi:10.1618/jhes.15.13
10.
LiYH. Study on the influence of building thermal environment on human thermophysiological response and experimental simulation. (In Chinese)New Archit2019; 5: 18–22.
11.
OhnakaTTochiharaYKuboM,YamaguchiC.Physiological and subjective responses to standing showers, sitting showers, and sink baths. J Physiol Anthropol1995; 14: 235–239.
12.
KandaKOhnakaTTochiharaYTsuzukiKShodaiYNakamuraK. Effects of the thermal conditions of the dressing room and bathroom on physiological responses during bathing. J Physiol Anthropol1996; 15: 19–24.
13.
OnoJHashiguchiNSatatariHOhkusaTMiyazonoMSonS-yMagotaCTochiharaYChishakiA.Effect of water bath temperature on physiological parameters and subjective sensation in older people. Geriatr Gerontol Int2017; 17: 2164–2170.
14.
LuoMHXuSTangYYuHZhouX.Experimental study on dynamic thermal responses and comfortable evaluations under bathing conditions. J Thermal Biol2023; 115: 103621.
15.
MiwaCShimasakiHMizutaniMMoriYMaedaKDeguchiA.Effect of aging on thermoregulatory and subjective responses during a 15-min bath at 41°C. J Hum-Environ Sys2020; 23: 45–53.
16.
OhnakaTTochiharaYWatanabeY. The effects of variation in body temperature on the preferred water temperature and flow rate during showering. Ergonomics1994; 37: 1–20. doi:https://doi.org/10.1016/0013-9351(67)90002-3
17.
de DearRJRingJWFangerPO. Thermal sensations resulting from sudden ambient temperature changes. Indoor Air1993; 3: 181–192.
18.
ZhangH. Human thermal sensation and comfort in transient and non-uniform thermal environment. Doctorate thesis. Berkeley: University of California, 2003.
19.
HuSHeMZhangXGuanHSongPLiuRLiuG.Cold and hot step-changes affecting thermal comfort and physiological indicators in winter. Energy Build2022; 254: 111587.
20.
HabibiPRezaeiSDehghanH,MaghsoudiK. The relationship between environmental and physiological heat stress indices in Muslim women under the controlled thermal conditions. Int J Environ Health Eng2015; 4: –6.
ChenQWangJTianJTangXYuCMarshallRJChenDCaoWZhanSLvJLeeL.Association between ambient temperature and blood pressure and blood pressure regulators: 1831 hypertensive patients followed up for three years. (In Chinese) Plos One2013; 8: 1–7. doi:10.1371/journal.pone.0084522
CohenJ. Statistical power analysis for the behavioural sciences. Totnes, Devon: Academic Press, 2013.
26.
LanLLianZ. Application of statistical power analysis–how to determine the right sample size in human health, comfort and productivity research. Build Environ2010; 45: 1202–1213.
27.
ZhaiYLiZChenXXieXZhuLLeiYQiuXFanZWangBLiuM.Thermal perception of non-uniform and dynamic air-conditioned environment in the elderly. J Build Eng2023; 76: 107236.
28.
WS/T 802-2022. China healthy elderly standard. Beijing: National Health Commission of the People’s Republic of China, 2022.
29.
YingYShiPLiYTanXLiY HHokoiS.Study on a thermophysiological model for health assessment of showering environment in China. J Phys Conf Ser2021; 2069: 012179.
30.
ASHRAE Standard 55-2020. Thermal environmental conditions for human occupancy. Atlanta: ASHRAE, 2021.
YangJWengWGZhangBT. Experimental and numerical study of physiological responses in hot environments. J Thermal Biol2014; 45: 54–61.
35.
WuYZhangZLiuHLiBChenBKosonenRJokisaloJ.Age differences in thermal comfort and physiological responses in thermal environments with temperature ramp. Build Environ2023; 228: 109887.
36.
WanLZhaoQ. The effect of thermal environment on heart rate of the elderly in heilongjiang province. Adv Intell Syst Res2020; 254: 558–562.
