The influence of internal and skin temperatures on active cutaneous vasodilation under different levels of exercise and ambient temperatures in humans.

To clarify the influence of internal and skin temperature on the active cutaneous vasodilation during exercise, the body temperature thresholds for the onset of active vasodilation during light or moderate exercise under different ambient temperature conditions were compared. Seven male subjects performed 30 min of a cycling exercise at 20 % or 50 % of peak oxygen uptake in a room maintained at 20, 24, or 28 °C. Esophageal (Tes) and mean skin temperature (Tsk) as measured by a thermocouple, deep thigh temperature (Tdt) by the zero-heat-flow (ZHF) method, and forearm skin blood flow by laser-Doppler flowmetry (LDF) were monitored.

Relationship between mean body temperature calculated by two- or three-compartment models and active cutaneous vasodilation in humans: a comparison between cool and warm environments during leg exercise.

The aim of this study was to assess whether the three-compartment model of mean body temperature (Tb3) calculated from the esophageal temperature (Tes), temperature in deep tissue of exercising muscle (Tdt), and mean skin temperature (Tsk) has the potential to provide a better match with the thermoregulatory responses than the two-component model of mean body temperature (Tb2) calculated from Tes and Tsk. Seven male subjects performed 40 min of a prolonged cycling exercise at 30% maximal oxygen uptake at 21°C or 31°C (50% relative humidity). Throughout the experiment, Tsk, Tb2, Tb3, and Tdt were significantly (P < 0.