Which physiological measurements can characterize core and surface body temperature? A case study in stable thermal environment

Abstract

Core and surface body temperature are physiological indicators commonly used in human-environment researches, but which specific body temperatures can characterize them have not been thoroughly explored. A case study was conducted in three stable thermal environments, where five kinds of body temperatures (intra-abdominal temperature, oral temperature, auditory canal temperature, breath temperature, and skin temperature) and two types of thermal perception (thermal sensation and thermal comfort) votes were regularly collected. Upon comparing measurements with theoretical classification principles, we found that both oral temperature and intra-abdominal temperature exhibited characteristics consistent with core temperature, while both mean skin temperature and breath temperature exhibited characteristics consistent with surface temperature. In addition, the comparison analysis between newly proposed indicators and gold standards further confirmed application prospects, as the average temperature difference between intra-abdominal and oral remained consistently below 0.1 °C, and the average temperature difference between skin and breath exhibited a slight fluctuation around fixed values. Generally, the findings of this study provide insights into the selection and application of body temperature indicators, while reminding researchers should not blindly follow the previous standards.