Finger vasodilation correlates better with tympanic than esophageal temperature

Abstract

The relationship of finger blood flow (FBF) measured by venous occlusion plethysmography to tympanic temperature (T_ty) was compared with that of FBF to esophageal temperature (T_es) during exercise at 50% $\dot V_{O_{2max} }$ for 40 min at an ambient temperature of 25°C. The relationship of FBF to T_es showed an inflexion as T_es increased during exercise. The slope of the regression line showing the relationship between FBF and T_es was initially moderate, and then suddenly became steeper at the inflexion point. The relationship of FBF to T_ty, however, was linear, without an inflexion. The results suggest that finger vasodilation during moderate exercise correlates better with tympanic than esophageal temperature.