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Estimating changes in volume-weighted mean body temperature using thermometry with an individualized correction
Ollie Jay1, Michel B DuCharme, Paul Webb
1Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada. ojay@uottawa.ca
Summary
This study accurately estimates body temperature changes by accounting for metabolic heat production, body surface area, and environmental conditions. The findings improve thermometry models for better heat balance assessment during exercise.
Area of Science:
- Physiology
- Thermoregulation
- Exercise Science
Background:
- Accurate measurement of core body temperature is crucial for understanding thermoregulation during exercise.
- Existing thermometry models using core and skin temperatures have estimation errors.
- Personal and environmental factors may influence these estimation errors.
Purpose of the Study:
- To investigate if personal (metabolic heat production, body surface area, body fat percentage) and environmental (Oxford index) parameters can account for the estimation error in volume-weighted mean body temperature (DeltaT(b)) using a two-compartment thermometry model.
- To develop and validate a model that improves the accuracy of DeltaT(b) estimation.
Main Methods:
- Whole body calorimetry was used to directly measure DeltaT(b) in experimental and validation groups during cycle ergometry under various thermal conditions.
- A two-compartment model using rectal (core) and mean skin temperature (shell) was employed.
- Stepwise linear regression analyzed the association between estimation error (X(0)) and personal/environmental parameters in the experimental group.
- Regression models were used to predict and adjust DeltaT(b) in the validation group.
Main Results:
- Metabolic heat production (M - W), body surface area (BSA), and Oxford index significantly correlated with the thermometric estimation error (X(0)) at all time points and weightings.
- Body fat percentage (%fat) and body surface area-to-mass ratio (BSA/BM) did not significantly correlate with X(0).
- The adjusted DeltaT(b) (DeltaT(b)_(adj)) using a 0.66/0.34 core/shell weighting significantly improved accuracy, explaining 74-84% of the variation in DeltaT(b) from calorimetry in the validation group.
Conclusions:
- Personal factors like metabolic heat production and body surface area, along with environmental conditions, are key determinants of thermometry model accuracy for estimating body temperature during exercise.
- The developed model successfully adjusted DeltaT(b) estimations, significantly enhancing their reliability.
- This research provides a more accurate method for assessing body heat balance in diverse environmental conditions and exercise intensities.
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Step 1: Perform hand hygiene and don clean gloves to prevent cross-infection.
Step 2: Position the patient in a side-lying position to better visualize the rectal...
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Step 1: Perform hand hygiene and don clean gloves to prevent cross-infection.
Step 2: Position the patient in a side-lying position to better visualize the rectal...
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