Prediction of human core body temperature using non-invasive measurement methods

Abstract

The measurement of core body temperature is an efficient method for monitoring heat stress amongst workers in hot conditions. However, invasive measurement of core body temperature (e.g. rectal, intestinal, oesophageal temperature) is impractical for such applications. Therefore, the aim of this study was to define relevant non-invasive measures to predict core body temperature under various conditions. We conducted two human subject studies with different experimental protocols, different environmental temperatures (10 °C, 30 °C) and different subjects. In both studies the same non-invasive measurement methods (skin temperature, skin heat flux, heart rate) were applied. A principle component analysis was conducted to extract independent factors, which were then used in a linear regression model. We identified six parameters (three skin temperatures, two skin heat fluxes and heart rate), which were included for the calculation of two factors. The predictive value of these factors for core body temperature was evaluated by a multiple regression analysis. The calculated root mean square deviation (rmsd) was in the range from 0.28 °C to 0.34 °C for all environmental conditions. These errors are similar to previous models using non-invasive measures to predict core body temperature. The results from this study illustrate that multiple physiological parameters (e.g. skin temperature and skin heat fluxes) are needed to predict core body temperature. In addition, the physiological measurements chosen in this study and the algorithm defined in this work are potentially applicable as real-time core body temperature monitoring to assess health risk in broad range of working conditions.

Considerations for the measurement of core, skin and mean body temperatures

“…Recently, Xu et al (2013) and Niedermann et al (2014) predicted deep-body temperature from skin temperatures, transcutaneous heat fluxes and heart rate. Unfortunately, those models were validated against gastrointestinal and rectal temperatures, the thermal inertia of which limited their utility.…”

Challenges of measuring body temperatures of free-ranging birds and mammals

“…Studies relying on remote sensing techniques should, therefore, take proper care to carefully calibrate sampling methods against other regions of the body to assess the extent to which peripheral temperature reflects internal and external temperature. One useful approach that may aid choice of the most reliable/consistent indicator of internal temperature has been to apply multivariate statistical techniques such as principle component analysis to multiple peripheral measurements [108].…”

Effect of perspiration on skin temperature measurements by infrared thermography and contact thermometry during aerobic cycling

“…In case of wireless sensors, they provide test participants with great mobility as they do not interfere with their physical activity (10,11). These sensors allow a continuous recording of the temperature in high-dynamic situations or below or in-between clothing layers (12). Although the validity of wireless temperature sensors is accepted (11,13), determining temperature in just one single point can limit the understanding of human thermal response as the evaluated body part could be not properly represented.…”