School of Mechanical Engineering, Tongji University, Shanghai, 201804, China.
School of Mechanical Engineering, Tongji University, Shanghai, 201804, China.
J Therm Biol. 2023 Jul;115:103621. doi: 10.1016/j.jtherbio.2023.103621. Epub 2023 Jun 18.
This study investigated the dynamic thermal responses and comfortable boundaries under different bathing conditions through a series of human subject experiments. Eleven subjects' subjective questionnaires and physiological parameters were collected. During the 40-min 40 °C bath, subjects' whole-body thermal sensation, sweating sensation, and fatigue relieving vote increased from 0 (neutral) to 2.6 (near 'hot' sensation), 3.5 (near 'very sweaty' sensation), and 1.6 (near 'relieved' vote), respectively. Thermal comfort vote firstly increased to 1.5 (near 'comfortable' sensation) in the first 10 min, then decreased to -0.5 (between 'neutral and slightly uncomfortable' sensation), and eventually remained around 1.1 ('slightly comfortable' sensation) after the bath. After the 40-min bath, the skin temperature and core temperature rose by 2.0 °C and 0.9 °C respectively. The mean heart rate increased by 45% and blood pressure decreased in most subjects. The percentage of β brain wave (representing concentration emotion) decreased while that of δ brain wave (representing relaxing emotion) increased, indicating that the bathed subjects tended to be more relaxed and sleeping emotionally. Based on these observations, we inferred that bathing thermal comfort can be influenced by multiple factors simultaneously but effective evaluation tools quantifying bathing thermal comfort are yet to be produced. Compared with showering, bathing usually induces more intensive thermal stress to the body, causing similar changing patterns but stronger amplitudes in subjective and physiological responses. These results can provide references for more comfortable and healthier bathroom environment design and relevant environmental conditioning products.
本研究通过一系列人体实验，探讨了不同沐浴条件下的动态热响应和舒适边界。收集了 11 名受试者的主观问卷和生理参数。在 40 分钟 40°C 的沐浴过程中，受试者的全身热感觉、出汗感觉和疲劳缓解评分从 0（中性）增加到 2.6（接近“热”感觉）、3.5（接近“非常出汗”感觉）和 1.6（接近“缓解”评分）。热舒适评分在最初的 10 分钟内从 1.5（接近“舒适”感觉）增加，然后降至-0.5（在“中性和略微不舒适”感觉之间），在沐浴结束后最终保持在 1.1（略微舒适）左右。沐浴 40 分钟后，皮肤温度和核心温度分别升高 2.0°C 和 0.9°C。大多数受试者的平均心率增加了 45%，血压下降。β 脑电波（代表专注情绪）的百分比下降，而 δ 脑电波（代表放松情绪）的百分比增加，这表明沐浴后的受试者往往更加放松和情绪化地进入睡眠状态。基于这些观察，我们推断沐浴的热舒适可以受到多种因素的同时影响，但仍需要开发有效的评估工具来量化沐浴的热舒适感。与淋浴相比，沐浴通常会给身体带来更强烈的热应激，导致主观和生理反应的变化模式相似，但幅度更大。这些结果可为更舒适、更健康的浴室环境设计和相关环境调节产品提供参考。
