Chinese elderly's thermo-physiological responses to transient temperature during showering process in winter: Evidence at a nursing home in Chongqing

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.