TY - JOUR
T1 - Comparing the efficacy of different climate indices for prediction of labor loss, body temperatures, and thermal perception in a wide variety of warm and hot climates
AU - Havenith, George
AU - Smallcombe, James W
AU - Hodder, Simon
AU - Jay, Ollie
AU - Foster, Josh
N1 - Publisher Copyright:
t © 2024 The Authors.
PY - 2024/8/1
Y1 - 2024/8/1
N2 - The purpose of this study was to investigate which climate/heat indices perform best in predicting heat-induced loss of physical work capacity (PWC
loss). Integrating data from earlier studies, data from 982 exposures (75 conditions) exercising at a fixed cardiovascular load of 130 beats·min
-1, in varying temperatures (15–50
°C), humidities (20–80%), solar radiation (0–800 W·m
-2), wind (0.2–3.5 m·s
-1), and two clothing levels, were used to model the predictive power of ambient temperature, universal thermal climate index (UTCI), wet bulb globe temperature (WBGT), modified physiologically equivalent temperature (mPET), heat index, apparent temperature (AT), and wet bulb temperature (T
wb) for the calculation of PWC
loss, skin temperature (T
skin) and core-to-skin temperature gradient, and thermal perception (thermal sensation vote, TSV) in the heat. R
2, RMSE, and Akaike information criterion were used indicating model performance. Indices not including wind/radiation in their calculation (T
a, heat index, AT, and T
wb) struggled to provide consistent predictions across variables. For PWC
loss and TSV, UTCI and WBGT had the highest predictive power. For T
skin, and core-to-skin temperature gradient, the physiological models UTCI and mPET worked best in seminude conditions, but clothed, AT, WBGT, and UTCI worked best. For all index predictions, T
a, vapor pressure, and T
wb were shown to be the worst heat strain predictors. Although UTCI and WBGT had similar model performance using the full dataset, WBGT did not work appropriately in windy, hot-dry, conditions where WBGT predicted lower strain due to wind, whereas the empirical data, UTCI and mPET indicated that wind in fact increased the overall level of thermal strain. The findings of the current study highlight the advantages of using a physiological model-based index like UTCI when evaluating heat stress in dynamic thermal environments.
AB - The purpose of this study was to investigate which climate/heat indices perform best in predicting heat-induced loss of physical work capacity (PWC
loss). Integrating data from earlier studies, data from 982 exposures (75 conditions) exercising at a fixed cardiovascular load of 130 beats·min
-1, in varying temperatures (15–50
°C), humidities (20–80%), solar radiation (0–800 W·m
-2), wind (0.2–3.5 m·s
-1), and two clothing levels, were used to model the predictive power of ambient temperature, universal thermal climate index (UTCI), wet bulb globe temperature (WBGT), modified physiologically equivalent temperature (mPET), heat index, apparent temperature (AT), and wet bulb temperature (T
wb) for the calculation of PWC
loss, skin temperature (T
skin) and core-to-skin temperature gradient, and thermal perception (thermal sensation vote, TSV) in the heat. R
2, RMSE, and Akaike information criterion were used indicating model performance. Indices not including wind/radiation in their calculation (T
a, heat index, AT, and T
wb) struggled to provide consistent predictions across variables. For PWC
loss and TSV, UTCI and WBGT had the highest predictive power. For T
skin, and core-to-skin temperature gradient, the physiological models UTCI and mPET worked best in seminude conditions, but clothed, AT, WBGT, and UTCI worked best. For all index predictions, T
a, vapor pressure, and T
wb were shown to be the worst heat strain predictors. Although UTCI and WBGT had similar model performance using the full dataset, WBGT did not work appropriately in windy, hot-dry, conditions where WBGT predicted lower strain due to wind, whereas the empirical data, UTCI and mPET indicated that wind in fact increased the overall level of thermal strain. The findings of the current study highlight the advantages of using a physiological model-based index like UTCI when evaluating heat stress in dynamic thermal environments.
UR - http://www.scopus.com/inward/record.url?scp=85201436964&partnerID=8YFLogxK
U2 - 10.1152/japplphysiol.00613.2023
DO - 10.1152/japplphysiol.00613.2023
M3 - Article
C2 - 38867664
SN - 0161-7567
VL - 137
SP - 312
EP - 328
JO - Journal of applied physiology (Bethesda, Md. : 1985)
JF - Journal of applied physiology (Bethesda, Md. : 1985)
IS - 2
ER -