Whole-Body Cooling Following Exercise-Induced Hyperthermia: Biophysical Considerations

Abstract

This thesis examined the effect of differences in body surface area-to-lean body mass ratio (AD/LBM) on core temperature cooling rates during cold water immersion (2°C, CWI) and temperate water immersion (26°C, TWI) following exercise-induced hyperthermia (end-exercise rectal temperature of 40°C). Individuals with a High AD/LBM (315 cm2/kg) had a ~1.7-fold greater overall rectal cooling rate relative to those with Low AD/LBM (275 cm2/kg) during both CWI and TWI. Further, overall rectal cooling rates during CWI were ~2.7-fold greater than during TWI for both the High and Low AD/LBM groups. Study findings show that AD/LBM must be considered when determining the duration of the immersion period. However, CWI provides the most effective cooling treatment for EHS patients irrespective of physical differences between individuals.