During the 1960~80s Korean breath-hold women divers (haenyeo) received attention from environmental physiologists, especially Professor Suk-Ki Hong and colleagues, due to their unique ability to resist cold water wearing only a thin cotton bathing suit (so-jung-ee). Eventually, Haenyeos began to wear wetsuits to avoid severe cold stress instead of the cotton bathing suit from the mid 1970’s.With advancing social industrialization, the number of haenyeos rapidly decreased and a total of 4,507 haenyeos works as of 2013. The average age of haenyeos is 70 years old and the oldest haenyeos currently diving is 92 years old. Today, some senior haenyeos over fifty years old share the diving experiences of their youth by wearing the classic cotton bathing suits. At present it is predicted that the tradition of haenyeos could cease to exist in 10-15 years because of their aging. At this point in time, it is worth reviewing the history of haenyeos’ diving practices and acclimatization/deacclimatization to cold. The present review described the diving practices and physiology of haenyeos related to cotton bathing suits and wetsuits. Finally, we suggest interdisciplinary research on haenyeos from the viewpoint of social-environmental physiology and intangible cultural heritage.

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The article aims to investigate residents’ cooling behaviors and to examine the possibilities for reducing thermal discomfort, changing the duration of air-conditioner use, and reducing cooling load through behaviors influencing visual, auditory and other sensation. A questionnaire was administered in Kyoto, Japan during summer 2010. The results indicated that: (a) to cool down, many residents engage in daily cooling behaviors other than using air-conditioners, such as using rugs, sprinkling water, bamboo blinds, and having coolcolored interior elements. In addition, many of these behaviors were negatively correlated with the length of air-conditioner use; (b) cooling behaviors include acts to lower the temperature (e.g., sprinkling water and bamboo blinds) and acts to obtain non-heat-related cooling effects (e.g., using rugs, a cool-colored interior, scents with cooling effects, wind chimes, music with cooling effects); (c) a comparison between the simulated cooling load of four groups (categorized according to the use of bamboo blinds and a cool-colored interior) found that the cooling load of the group using both is about 10% lower than the group using neither.

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In order to quantitatively assess the individual differences in the thermophysiological responses, human subjects were exposed to a series of stepwise air temperature changes, and the rectal and skin temperatures and weight change were measured. The differences between subject responses were evaluated not only for steady state but also for a transient state. Ten young males were used as subjects and were monitored in a sedentary state. From the results of the transient exposure to cold and hot environments for 150 min. (29 ℃, 30 min. – 20 ℃, 20 min. – 29 ℃, 60 min. – 38 ℃, 20 min. – 29 ℃, 20 min.), it was shown that the individual differences in rectal temperatures amounted to a standard deviation of 0.3 K, and that for mean skin temperature the standard deviation was 0.5 K for both steady and transient states. Local skin temperatures, measured at seven points to represent each body segment, showed larger individual differences than those for mean skin temperature, which suggests the existence of individual differences in skin temperature distributions. In addition, the skin temperature time derivative at the beginning of a step change in air temperature and body weight change were studied from the viewpoint of the individual difference. It was shown that the individual differences in rectal temperature, skin temperature distribution, and sweat rate were significant, and that the difference between individuals for skin temperature change during the transient state was almost the same as that for the thermally neutral and steady state. Furthermore, correlations between the responses and basic body parameters (the body weight, body surface area, and body fat percentage of the subjects) were studied using correlation analysis. As the results indicated, body fat percentage had greater influence on thermophysiological responses than height, body weight and surface area, and the correlation coefficients were fairly high for each of the thermophysiological responses measured in this study. For the thermally neutral and steady state data, rectal temperature showed a positive correlation with body fat percentage, while mean skin temperature showed a negative correlation with body fat percentage. These findings suggest that body fat percentage might be a promising parameter for explaining individual differences in thermophysiological responses.

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