This study investigated the effect of ice pack cooling on exercise-induced elevation of body temperature in warm and humid conditions.
　Eight male subjects performed an exercise test in high temperature (35℃) and humid conditions (70%) at 70% maximal oxygen uptake (VO₂max) for 10 minutes after 15 minutes resting and warming up for 5 minutes. After the exercise, subjects remained in these conditions for 30 minutes. Subjects were randomly assigned to groups with an ice pack or without an ice pack (non-ice pack) .
　Body temperature in the rectum (TRe), trunk skin (TTr), and axillary skin (TAx), and subjective feeling were measured during the experiments. TTr was the skin temperature around the ice pack and TAX was that beneath the ice pack. Body weight was measured before and after the experiment.
　TRe was not different between groups, but TTr and TAx were significantly lower in the ice pack group those in the non-ice pack group until the end of the experiment (p<0.05). Body weight was significantly decreased after the experiment in both groups (p<0.05) ; however, this change was smaller in the ice pack group (p<0.05).
　The changes of subjective feelings of sensory temperature and motivation were significantly different between the ice pack and non-ice pack groups (p<0.05).
　This study suggests that wearing an ice pack decreases exercise-induced dehydration, which could contribute to prevention of heat stroke. In addition, the ice packs used in this study sustained the cooling effects for 60 minutes in a high temperature.

DESCENTE SPORTS SCIENCE Vol.33/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE