Effects of plateau thermal environment stressors on thermal acclimation of sojourners from different climates

The Qinghai-Tibet Plateau is cold and dry, and creating a suitable indoor environment is a prerequisite for ensuring the normal life of sojourners in mainland China. Sojourners from the plains experienced geographical spans and faced changes in the thermal and humid environments, and their thermal acclimation characteristics differed from plains and plateau residents. In this study, the intensities of thermal and humid stresses were classified according to changes in outdoor temperature and humidity caused by migration. The temperature was divided into five grades: A, B, C, D, and E, with an interval of 5 °C; humidity was divided into four grades: a, b, c, and d, with a relative humidity interval of 20%. A nationwide questionnaire survey was conducted to obtain subjective evaluations of sojourners, plains and plateau residents. Reliability and validity tests were conducted for the questionnaire. The results showed that previous exposure significantly influenced the thermal and humid expectation levels. Compared with plains residents, the proportion of sojourners who felt cold and dry increased. Sojourners from region D were less accepting of indoor temperature and had the strongest desire to improve indoor humidity, with an average humid preference vote (HPV) value of 1.7. The present study provided implications for the thermal comfort of plateau sojourners from the perspective of comprehensive demand of thermal and humid environments. •Multi-level stress intensities of environment of sojourners were classified.•Thermal and humid adaptation levels under multi-level stress intensities were studied.•The creation of thermal and humid environments was equally important for plateau sojourners.•The stronger the stress intensity of sojourners, the poorer the adaptability to the plateau environment.