This research theme investigates human physiological and behavioral responses to thermal conditions that fall outside the range assumed by current comfort standards. The comfort envelope, as defined by decades of thermal comfort science, was developed to characterize the conditions under which a healthy sedentary adult reports thermal neutrality. Substantial evidence, however, indicates that the human body is capable of maintaining function, thermal balance, and well-being across a much broader range of conditions than this envelope reflects, and that populations exposed to sustained variability show adaptive responses with implications for how buildings should be designed and operated. Our work examines these responses across contrasting populations and controlled experimental settings, with the aim of informing a next generation of building science that treats the body as an active partner rather than a passive occupant.
Contrasting Populations, Contrasting Adaptations:
The featured study within this research theme is a matched comparison of thermal physiology between two contrasting populations: semi-nomadic herders in Tuva (Southern Siberia), living year-round in traditional yurts across severe winters, and urban Dutch residents of Maastricht, living in centrally heated dwellings within a narrow thermal range. Participants in both cohorts were characterized under controlled laboratory conditions using standardized cold exposure protocols, alongside free-living measurements of energy expenditure, core and skin temperatures, and daily thermal exposure patterns.
The comparison reveals that the Tuvan cohort maintains thermal balance across substantially broader ambient conditions than the Maastricht cohort, with adaptations extending across metabolism, peripheral vasoregulation, and behavior. Behavior in particular emerges as a distinct and substantial component of the adaptive response, including:
- Active management of thermal exposure across the day
- Layering and adjustment of clothing in response to changing conditions
- Sustained stove use during occupied periods in the yurt
- Coordination of daily routines around the thermal environment rather than against it
Together, the physiological and behavioral findings illustrate the plasticity of human thermoregulation in ways that current comfort standards, calibrated on populations resembling the Maastricht cohort, do not capture, and suggest that occupant behavior should be treated as a co-equal mechanism of adaptation rather than as noise around a physiological baseline.
JOURNAL PUBLICATIONS:
- Khovalyg D. et al. (2023) Behavioral adaptations to cold environments: A comparative study of active nomadic and modern sedentary lifestyles, Building and Environment, 243, 110664. DOI: 10.1016/j.buildenv.2023.11.
- Sellers et al. (2023) Thermoregulation of Tuvan pastoralists and Western Europeans during cold exposure, American Journal of Human Biology, e23933. DOI: 10.1002/ajhb.23933
- Sellers et al. (2022) High daily energy expenditure of Tuvan nomadic pastoralists living in an extreme cold environment, Scientific Reports, 12:20127. DOI: 10.1038/s41598-022-23975-3
CONFERENCE PUBLICATIONS:
- Khovalyg & Purev (2024) Harnessing Traditional Living Experience to Foster Resilience in Modern Living.CATE 2024, 20-24 November 2024, Seville, Spain. Infoscience link