HF model parameters.

Humans are exposed to daily temperature differences indoors and outdoors worldwide; however, the associated risks to health and fatigue remain unclear. This study aimed to clarify the psychophysiological loads by repeated short-term temperature differences on Japanese individuals. Herein, 28 healthy individuals were repeatedly moved between two temperature environments, and their psychological/physiological responses to temperature differences in the environment were recorded [T26-26 (control), T26-31 (5 °C step), T26-36 (10 °C step), and T21-36 (15 °C step)]. We precisely estimated the accumulated effects (load) of repeated temperature steps using a Bayesian state–space model, and distinguished them from the direct effects of environmental changes. The Load to the autonomic nervous system was continuously enhanced (decreased high-frequency of RRI and increased low-frequency/high-frequency of RRI) in the trials with temperature steps, while it was less under the T21-36 (15 °C step) than under the T26-36 (10 °C step) condition. These findings could help formulate fatigue management approaches and recommend best practices to minimise adverse health effects related to sudden and uncontrollable environmental temperature steps/changes in everyday scenarios on the public.

全球范围内，人类日常均会暴露于室内外的温差环境中，但此类温差对健康与疲劳的潜在关联风险仍未明确。本研究旨在阐明反复短时温差暴露对日本个体造成的心理生理负荷。本研究中，28名健康受试者被反复切换至两种温度环境，并记录了其对环境温差的心理与生理反应，实验分组包括T26-26（对照组）、T26-31（5℃阶跃）、T26-36（10℃阶跃）及T21-36（15℃阶跃）。本研究采用贝叶斯状态空间模型（Bayesian state–space model）精准估算了反复温度阶跃带来的累积效应（即负荷），并将其与环境变化的直接效应加以区分。在温度阶跃实验中，受试者自主神经系统所承受的负荷持续升高，具体表现为R-R间期（RRI）的高频成分降低、低频/高频比值升高；且T21-36（15℃阶跃）组的负荷低于T26-36（10℃阶跃）组。本研究结果可为制定疲劳管理方案提供理论支撑，并可为日常场景中公众应对突发、不可控的环境温度阶跃/变化以降低不良健康影响提供最优实践建议。