Abstract
This study examines the body cooling effects of immersion in high-concentration artificial carbonic acid water.
The subjects’ core (tympanic) temperature was increased by a pedaling ergometer. They then immersed their
lower legs in carbonic acid water or tap water. The decrease in tympanic temperature was observed. The tympanic
temperature significantly decreased more during immersion in stirred 25 / 30°C CO2 water than in tap water. The
results suggest that immersing the lower legs in stirred 25 / 30°C carbonic acid water can suppress skin vascular
constriction and reduce core temperature elevated by heat stress / exercise more effectively than stirred tap water of
the same water temperature.
