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Estimating Core Temperature during Exercise in Heat Using Non‐Invasive Measurements
Author(s) -
Xu Xiaojiang,
Karis Anthony J,
Mullen Stephen P,
Patel Tejash,
Buller Mark J,
Santee William R
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.1084.13
Subject(s) - torso , core (optical fiber) , limits of agreement , core temperature , chemistry , sternum , intensity (physics) , treadmill , mathematics , nuclear medicine , zoology , medicine , surgery , materials science , anatomy , physics , quantum mechanics , biology , composite material
The goal was to develop a non‐invasive method to estimate core temperature (Tc) from a combination of skin temperature (Ts) and heat flux (HF) during exercise in the heat. Nine test volunteers participated in three sessions at 25°C/50% RH; 35°C/75% RH; and 42°C/20%RH. Each session consisted of two 1 hour treadmill walks at ~300 W and ~550 W intensity separated by a 30 min break. Tc, heart rate and Ts/HF from 6 sites on the head, thigh, and torso were measured. Correlation analysis was used to select individual sites that showed a close association between Tc and Ts/HF. Multiple regression analysis was then used to derive equations (EQ) to estimate Tc from Ts/HF using 3 sites on the torso: the sternum (ST), the pectoralis muscle (PE) and the scapula (SC). For EQ developed using Ts/HF at each individual site, the coefficients of determination (R2) were 0.82, 0.86 and 0.86 for PE, ST and SC respectively. For EQ developed using Ts/HF from both ST and SC (EQ‐SS), R2 was 0.92. EQ‐SS was evaluated for accuracy using the validation data (n=4). The root mean square error (RMSE) for each individual ranged from 0.20°C to 0.26°C and R2 from 0.8 to 0.9. For Tc <38°C, a less critical zone, differences between predicted and measured Tc were higher. For Tc >38°C, a more critical zone, the differences were smaller; most were within 0.4°C. Thus this method appears to be viable for Tc monitoring for the prevention of heat illness and injury.