Yumiko Nagai

In a pilot study, we observed the state of "heat shock" in elderly persons living in Osaka and Akita by means of simulating bathing and excretion in winter. Furthermore, using data on indoor thermal environments collected nationwide, we investigated relationships between heating equipment and air temperature in bathrooms and toilets, temperature differences from living rooms, and thermal sensations for the elderly. The pilot study showed that differences in air temperature between living rooms and other rooms were larger in cold latitudes, where there was a subject with remarkably increased blood pressure when moving from the living room to the bathroom or the toilet. According to data from our nationwide survey, temperature differences between living rooms and bathrooms or toilets were the highest around eight o'clock in the evening. Despite similar thermal sensations, actual air temperatures in bathrooms and toilets were lower than those in living rooms. Elderly persons seemed to be tolerant to cold in bathrooms and toilets, although they might be stressed physically. Differences in temperature between living and bathrooms have a tendency to correlate with death rates from bathing.

A survey on thermal conditions of houses was carried out on 331 houses in 11 regions (Sapporo, Akita, Sendai, Chiba(north), Chiba(south), Shizuoka, Toyama, Osaka, Hiroshima, Fukuoka and Kagoshima) from December, 2004 to March, 2005. The air temperatures in the living room, bathroom, dressing room, toilet, corridor, bedroom and outdoor of houses were measured evety minute for 7 days. The water temperatures of bath during bathing were also recorded. The thermo-recorders which measured air temperatures at a height of 0.6-1.1m were kept out of the sun. The following results were obtained. (1) The room temperatures in Sapporo were kept above 15℃ in all rooms in winter. On the other hand, only living rooms were kept warm in the rest of regions. (2)The room temperatures in dressing rooms and/or corridors were vety low in all regions, except in Sapporo, (3)The mortality rate ofdrowninginthe 11 regions was correlated withthe room temperature in the dressing room.

This study investigated the bathing conditions of elderly Japanese, and sought to find factors relating to regional differences in death rates from bathtub accidents. A questionnaire survey was carried out in 11 areas of Japan. Questionnaires including questions regarding the length of time since houses had been built, types of facilities, and subjects' indoor thermal sensations and behavior while bathing were distributed to detached houses in each area twice, once in summer and once in winter. Completed questionnaires were collected from approximately 160 elderly people over 65 years old. Information regarding thermal sensations of rooms in winter revealed that a prefabricated bath and insulating window glass eased the cold in the bathroom. Unexpectedly, more subjects in the southern region than in the northern region reported being cold or a little cold while bathing in winter. In the present study, thermal sensations and behaviors while bathing seemed to be more affected by facilities and the location of houses than by the sex and age of the subjects.

The purpose of this research was to examine effect of the sports shoes which change shape by use on lumbar part and lower limbs. Subjects were 251 people who belong to a college student track-and-field part. 1) Relation was accepted between the usable years of shoes, and injury of a waist and the leg. The injury of the thigh was occurring frequently to the person who used shoes seven months or more. The injury of the lower legs and foot were occurring frequently to the person who used shoes less than six months. 2) Those to whom the tiptoe inner side of an out sole was worn out have the high danger that injury would occur in the thigh and lower limbs. Those to whom the out sole heel outside was worn out have the high danger that injury would occur in lower limbs. Additionally, those to whom both the out sole heel outside and the tiptoe inner side of an out sole were worn out have the high danger that injury would occur in lower limbs. 3) Relation was not accepted between wear of the heel partial outside of an out sole, and supination injury. Furthermore, relation was not accepted between wear of a shoes inner side, and pronation injury. 4) Use of shoes seven months or more wears the heel outside of an in sole, and the root portion of the little toe of an out sole. However, relation was not accepted between other wear parts and usable years of shoes.

The purpose of this study was to compare bathing conditions in each area of Japan and to find the features of them in order to investigate factors affecting regional differences in death rates in the bathroom. In this study, a questionnaire survey was carried out in 11 areas, Sapporo, Akita, Sendai, northern and southern Chiba, Shizuoka, Toyama, Osaka, Hiroshima, Fukuoka, and Kagoshima. Questionnaires were distributed to approximately 30 detached houses in each area twice in summer and winter. Subjects were asked on passed years after building their houses, fixtures and thermal sensations in the houses, behaviors during bathing, and so on. Answers showed the regional differences in bathing conditions among areas as follows: From the view points of retentiveness and insulation of heat, newer and northern houses are better than older and southern ones. Unexpectedly, subjects of the southern areas reported colder thermal sensation in the bathroom in winter than those of the northern areas. There were regional differences in frequency and duration of bathing, and the person who take a bath first It seems that there may be the relationship between the bathing condition in each area and death rates in the bathroom, but ftirther investigations are needed.

We evaluated human physiological responses and the performance of manual tasks during exposure to severe cold (-25 degreesC) at night (0300-0500 hours) and in the afternoon (1500-1700 hours). Thirteen male students wearing standard cold protective clothing occupied a severely cold room (-25 degreesC) for 20 min, and were then transferred to a cool room (10 degreesC) for 20 min. This pattern of exposure was repeated three times, for a total time of exposure to extreme cold of 60 min. The experiments were started either at 1500 hours or 0300 hours and measurements of rectal temperature, skin temperature, blood pressure, performance in a counting task, hand tremor, and subjective responses were made in each condition. At the end of the experiment at night the mean decrease in rectal temperature [0.68 (SEM 0.04)degreesC] was significantly greater than that at the end of the experiment in the afternoon [0.55 (SEM 0.08)degreesC, P < 0.01]. After the second cold exposure at night the mean increase in diastolic blood pressure [90 (SEM 2.0) mmHg] was significantly greater than that at the end of the second cold exposure in the afternoon [82 (SEM 2.8) mmHg, P < 0.01]. At the end of the second cold exposure at night, mean finger skin temperature [11.8 (SEM 0.8)degreesC] was significantly higher than that at the comparable time in the afternoon [9.0 (SEM 0.7)degreesC, P < 0.017. Similarly for the toe, mean skin temperature at the start of the second cold exposure at night [25.6 (SEM 1.5)degreesC] was significantly higher than in the afternoon [20.1 (SEM 0.8)degreesC, P <0.01]. The increased skin temperatures in the periphery resulted in increased heat loss. Since peripheral skin temperatures were highest at night, the subjects noted diminished sensations of thermal cold and pain at that time. Manual dexterity at the end of the first cold exposure at night [mean 83.7 (SEM 3.6) times(.)min(-1)] had decreased significantly more than at the end of the first cold exposure in the afternoon [mean 89.4 (SEM 3.5) times (.) min(-1) P < 0.01]. These findings of a lowered rectal temperature and diminished manual dexterity suggest that there is an increased risk of both hypothermia and accidents for those who work at night.

Five healthy young and elderly female volunteers slept from 23:00 to 7:00 in a climate chamber that was controlled at 13℃ 60% RH. The lower extremity area of the futon was heated by using an electric blanket before sleep. Bed climate, body movement, skin temperature (T_<sk>), and heart rate were measured continuously throughout the night. Subjective sensational and sleep evaluations were conducted before and after the recording sessions. The bed climate of the foot area was significantly lower in the elderly. During wake, the finger and toe T_<sk> was significantly higher in the elderly, while that of the chest was lower. During sleep, the chest and mean T_<sk> were significantly higher in the young. The sleep maintenance factor of the subjective sleep evaluation was significantly better in the elderly. These results suggest that chest and mean T_<sk>, bed climate of the foot area and subjective sleep evaluation when an electric blanket is used before sleep may differ depending on age. The usage and the temperature level setting of the electric blanket should be adjusted according to age.

In the maker's office space with a multi-board radiant cooling system, subjective response, e.g. thermal comfort, thermal sensation etc., and skin temperature of occupants were measured as well as thermal conditions, e.g. air temperature, air humidity, etc. We focused on the air temperature to evaluate the thermal condition, because air temperature is decreased by the multi-board type of radiant cooling system more than by the single-board type. It was shown that a radiant cooling system is suitable to use in an office and that mechanical ventilation is recommended to use together with a radiant cooling system.

In order to investigate the physical, economical, physiological and psychological aspects regarding ancient lighting, two series of experiment were performed. At first a darkroom (1.3×4.5 m, Ht: 2.7m) was constructed. In experiment I, illuminance and consumption rate of fuel were measured. The Japanese classic candle, plant oil and animal fat yield I.12, 0.30-0.62 and 0.05 Iux at 1.0 m distance, respectively. The illuminance was reduced to about 50% by andon which was a lighting tool of folkcraft. The burning duration of plant oil was about two weeks to 180 ml when it burned 4 hours per one day. In experiment II, 15 young females were examined regarding the visual properties such as visual acuity, readability of newspaper and discrimination of color under the simulated illumination of candle. The visual acuity was 0.42 under 0.16 Iux. It needed more than 1.44 Iux to read a newspaper.In the color discrimination test, yellowish green was most difficult, silver or long wave range colors were easy.

Subcutaneous fat is an essential element in shaping the body of human beings. In this research, skinfold thickness was measured specifically in 33 regions of the human body, including the abdomen and buttocks. Based on our measurements, the subcutaneous fat distribution was assessed for several age groups. The subjects were healthy Japanese women aged 20 to 58 years. Skinfold thickness was measured using the B-mode ultrasound methods, together with anthropometric measurement. A comparison was made between the following five age groups: early 20's, Iate 20's, 30's, 40's and 50's. The measured values for the early 20's group were used as the standard and the relationship between increase ratio of subcutaneous fat and age was studied. Through our research, we obtained data on the subcutaneous fat distribution in each age group. The largest change was observed between the ages of the early 20's and late 20's. The skinfold thickness measurements of the abdomen and buttocks was consistently around 10 mm for the early 20's, and increased up to 23.8 mm on the rear side section for the late 20's. This result indicates that the increase ratio varied depending on the part of body. Furthermore, the changes in skinfold thickness were different in specific parts of the abdomen and buttocks among different age groups. The difference in skinfold thickness between upper and lower sections of the abdomen also becomes more pronounced with age. Skinfold thickness increased significantly between the early 20's and late 20's. Among the body regions, measurements at the rear side showed the largest change with age; averaging 11.3 mm for the early 20's compared to 33.6 mm for the 50's. The subcutaneous fat distribution on the buttock also showed the differences wlth age, indicating changes in body shape. Using careful measurements of the abdomen and buttocks, subcutaneous fat distribution among each age group was determined as well as the variation in changes with the aging process.

In order to investigate the physical, economical, physiological and psychological aspects regarding ancient lighting, two series of experiment were performed. At first a darkroom (1.3×4.5 m, Ht: 2.7m) was constructed. In experiment I, illuminance and consumption rate of fuel were measured. The Japanese classic candle, plant oil and animal fat yield I.12, 0.30-0.62 and 0.05 Iux at 1.0 m distance, respectively. The illuminance was reduced to about 50% by andon which was a lighting tool of folkcraft. The burning duration of plant oil was about two weeks to 180 ml when it burned 4 hours per one day. In experiment II, 15 young females were examined regarding the visual properties such as visual acuity, readability of newspaper and discrimination of color under the simulated illumination of candle. The visual acuity was 0.42 under 0.16 Iux. It needed more than 1.44 Iux to read a newspaper.In the color discrimination test, yellowish green was most difficult, silver or long wave range colors were easy.

Subcutaneous fat is an essential element in shaping the body of human beings. In this research, skinfold thickness was measured specifically in 33 regions of the human body, including the abdomen and buttocks. Based on our measurements, the subcutaneous fat distribution was assessed for several age groups. The subjects were healthy Japanese women aged 20 to 58 years. Skinfold thickness was measured using the B-mode ultrasound methods, together with anthropometric measurement. A comparison was made between the following five age groups: early 20's, Iate 20's, 30's, 40's and 50's. The measured values for the early 20's group were used as the standard and the relationship between increase ratio of subcutaneous fat and age was studied. Through our research, we obtained data on the subcutaneous fat distribution in each age group. The largest change was observed between the ages of the early 20's and late 20's. The skinfold thickness measurements of the abdomen and buttocks was consistently around 10 mm for the early 20's, and increased up to 23.8 mm on the rear side section for the late 20's. This result indicates that the increase ratio varied depending on the part of body. Furthermore, the changes in skinfold thickness were different in specific parts of the abdomen and buttocks among different age groups. The difference in skinfold thickness between upper and lower sections of the abdomen also becomes more pronounced with age. Skinfold thickness increased significantly between the early 20's and late 20's. Among the body regions, measurements at the rear side showed the largest change with age; averaging 11.3 mm for the early 20's compared to 33.6 mm for the 50's. The subcutaneous fat distribution on the buttock also showed the differences wlth age, indicating changes in body shape. Using careful measurements of the abdomen and buttocks, subcutaneous fat distribution among each age group was determined as well as the variation in changes with the aging process.

The purpose of this study is to obtain some knowledge related to physiological and psychological effects of head heating by radiation on the vital body under varying conditions of the environmental temperature and physical activity. The study was proceeded with experiments 1 and 2 using 8 women, all in good health as subjects. In experiment 1, firstly the subject at rest was kept at an ambient temperature of 28℃ for 40 minutes. Then, moving to a room kept at an ambient temperature of 18℃ or 28℃ , the state at rest was maintained with head heating at 3 radiant intensities (without radiation, 35℃ and 40℃ of globe temperature) for a further 40 minutes. In experiment 2, continued from the same procedure of experiment 1, work on the ergometer was performed for 30 minutes with head heating at 2 radiant intensities (without radiation and 35℃ of globe temperature). Items measured were tympanic temperature, skin temperatures, heart rate, and subjective sensations. The principal results obtained are as follows: 1) Tympanic temperature, forehead skin temperature and score of thermal sensation of head increased, while the others decreased at 18℃ . 2) Decrease of scores was inhibited by head heating in finger skin temperature, toe skin temperature and heart rate. 3) When radiant intensities at 35℃ and 40'C were compared, statistical significant difference was noted in forehead skin temperature only, the difference of radiant conditions gives a little effect to the vital body. 4) Effects brought by head heating during rest decreased owing to the addition of work.

The purpose of this study is to obtain some knowledge related to physiological and psychological effects of head heating by radiation on the vital body under varying conditions of the environmental temperature and physical activity. The study was proceeded with experiments 1 and 2 using 8 women, all in good health as subjects. In experiment 1, firstly the subject at rest was kept at an ambient temperature of 28℃ for 40 minutes. Then, moving to a room kept at an ambient temperature of 18℃ or 28℃ , the state at rest was maintained with head heating at 3 radiant intensities (without radiation, 35℃ and 40℃ of globe temperature) for a further 40 minutes. In experiment 2, continued from the same procedure of experiment 1, work on the ergometer was performed for 30 minutes with head heating at 2 radiant intensities (without radiation and 35℃ of globe temperature). Items measured were tympanic temperature, skin temperatures, heart rate, and subjective sensations. The principal results obtained are as follows: 1) Tympanic temperature, forehead skin temperature and score of thermal sensation of head increased, while the others decreased at 18℃ . 2) Decrease of scores was inhibited by head heating in finger skin temperature, toe skin temperature and heart rate. 3) When radiant intensities at 35℃ and 40'C were compared, statistical significant difference was noted in forehead skin temperature only, the difference of radiant conditions gives a little effect to the vital body. 4) Effects brought by head heating during rest decreased owing to the addition of work.

This study was conducted to investigate the effects of different exposure rates on thermal responses with the total cold exposure time the same under each of the conditions. After resting in a warm room (25 degrees C) for 10 minutes, six male students wearing standard cold protective clothing entered an adjoining cold room (- 25 degrees C). Each 5-, 10- and 20-minute cold exposure was repeated 12, 6 and 3 times, respectively. Each cold exposure was followed by a similar duration of rest at 25 degrees C. Total cold exposure time was the same under the three conditions. Rectal temperature, skin temperatures, blood pressure, 17-hydroxycoyticoids (OHCS), counting task and subjective responses were measured. At the end of the cold exposure skin temperatures in the shorter exposures were higher than those in the other conditions, except on the foot. Discomfort due to cold was less in the shorter exposures and manifestation of discomfort was delayed. However, there were no differences among the three conditions in the fall of rectal temperature and urinary excretion of 17-OHCS, which are good indices of cold stress. Moreover, increase in blood pressure and decrease in counting task due to cold were not different among the three conditions. Even though the cold exposure time for each stay was short, when cold exposures were repeated frequently, cold stress of the whole body and decrease in manual task performance were the same as in the longer cold exposure.

This study was conducted to investigate the effects of different exposure rates on thermal responses with the total cold exposure time the same under each of the conditions. After resting in a warm room (25°C) for 10 minutes, six male students wearing standard cold protective clothing entered an adjoining cold room (— 25°C). Each 5-, 10- and 20-minute cold exposure was repeated 12, 6 and 3 times, respectively. Each cold exposure was followed by a similar duration of rest at 25°C. Total cold exposure time was the same under the three conditions. Rectal temperature, skin temperatures, blood pressure, 17-hydroxycoyticoids (OHCS), counting task and subjective responses were measured. At the end of the cold exposure skin temperatures in the shorter exposures were higher than those in the other conditions, except on the foot. Discomfort due to cold was less in the shorter exposures and manifestation of discomfort was delayed. However, there were no differences among the three conditions in the fall of rectal temperature and urinary excretion of 17-OHCS, which are good indices of cold stress, Moreover, increase in blood pressure and decrease in counting task due to cold were not different among the three conditions. Even though the cold exposure time for each stay was short, when cold exposures were repeated frequently, cold stress of the whole body and decrease in manual task performance were the same as in the longer cold exposure. © 1995 Taylor &amp Francis Group, LLC.

The purpose of this study was to investigate the effects of body temperature variations on subjects' preferred water temperature and flow rate during showers. Nine healthy women students took a shower before and after physical exercise (running on a treadmill for 30 min) and water immersion (immersing in the water of 25-degrees-C temperature for 30 min). During each shower, the subject was instructed to adjust both the water temperature and flow rate of a shower to suit their comfort. Rectal temperature and skin temperatures of the subjects, water temperature, and flow rate of the shower were measured during the experiments. The means of preferred water temperature during showers were 40.2-degrees-C and 43.8-degrees-C before and after water immersion respectively, which were significantly different. On the other hand, there was little difference in the preferred water temperature between before and after the treadmill exercise. There were no significant differences in the flow rates between before and after both water immersion and the treadmill exercise. A significant negative relationship was observed between the mean body temperature (T(b)BAR) and the preferred water temperature during showers (r = - 0.439). On the other hand, no significant relationship was found between T(b)BAR and the preferred flow rate. Moreover, a significant negative relationship was observed between the preferred water temperature and the flow rate during showers (r = - 0.528).

1. 10 elderly and 10 college-aged females served as subjects in cold and heat environments. The subjects changed into the standard clothing (0.63 clo), and stayed in the neutral environment (25 degrees C) for 23 min, thereafter they were exposed to the cold (10 degrees C) or hot (35 degrees C) environment for 49 min. 2. Then they returned to the neutral environment, and stayed there for 47 min. Oral temperature, skin temperatures at 10 sites, blood pressure and thermal sensation were measured during the experiments. 3. In the cold environment, the elderly could not reduce heat loss by vasoconstriction as did young people, and their blood pressures increased more rapidly than in young people. In the hot environment, the elderly could not promote heat loss by vasodilation as did young people. Moreover, there is a delayed sensitivity to cold for the elderly. Therefore, in the houses of the elderly, it is important to have heating and cooling systems which also includes the areas where the people do not stay for a long-period of time (e.g. toilet, passageways).

1. 10 elderly and 10 college-aged females served as subjects in cold and heat environments. The subjects changed into the standard clothing (0.63 clo), and stayed in the neutral environment (25 degrees C) for 23 min, thereafter they were exposed to the cold (10 degrees C) or hot (35 degrees C) environment for 49 min. 2. Then they returned to the neutral environment, and stayed there for 47 min. Oral temperature, skin temperatures at 10 sites, blood pressure and thermal sensation were measured during the experiments. 3. In the cold environment, the elderly could not reduce heat loss by vasoconstriction as did young people, and their blood pressures increased more rapidly than in young people. In the hot environment, the elderly could not promote heat loss by vasodilation as did young people. Moreover, there is a delayed sensitivity to cold for the elderly. Therefore, in the houses of the elderly, it is important to have heating and cooling systems which also includes the areas where the people do not stay for a long-period of time (e.g. toilet, passageways).

1. The purpose of the study was to investigate the preferred temperature of the elderly after cold and heat exposures. 2. Eight elderly and 9 young females wearing the same type of clothing were exposed to cold (10 degrees C), moderate (25 degrees C) or hot (35 degrees C) environments for 30 min in the exposure room. 3. Then they moved to the self-control room in which the temperature was set at 25 degrees C, and the room temperature increased or decreased continuously by 0.4 degrees C every minute. 4. The subjects were instructed to operate the switch when they felt uncomfortably warm or cool during a 90-min period. 5. In operating the switch, the changing in room temperature shifted to the opposite direction. 6. The ambient temperature was recorded continuously and analyzed as the preferred temperature, which was defined as the midpoint temperature of the crest and trough of temperature records. 7. The preferred temperatures after the cold exposure were significantly higher than those of other exposure conditions in the elderly. 8. On the other hand, in the young, there was no significant difference in the preferred temperature among the exposure conditions. 9. Although the effect of exposure to cold or hot environments decreased in the latter parts of self-control, the elderly still preferred the higher temperature after cold exposure.

1. Ten male students remained in a severely cold room (-25 degrees C) for 20 min, thereafter, they transferred in a warm room (25 degrees C) for 20 min. 2. This pattern was repeated three times, total cold exposure time amounting to 60 min. 3. In the warm room, the subjects removed their cold-protective jackets, or wore them continuously. 4. Rectal temperature, skin temperatures, manual performance and thermal comfort were measured during the experiment. 5. Removing cold-protective jackets after severe cold exposures increased peripheral skin temperatures and reduced the discomfort in the warm room. 6. However, these results were accompanied by a greater decrease in rectal temperature and manual performance. 7. It is recommended that workers continue to wear cold-protective clothing in the warm areas outside of the cold storage to prevent decreases in deep body temperature and work efficiency caused by repeated cold exposures.

Since the health hazard of asbestos fibers has been widely recognized, the number of asbestos abatement projects in schools has increased rapidly. Most of these projects were planned during summer vacation from school. However, in Japan, it is hot and humid in summer. Moreover, the workers have to wear impermeable protective clothing because of the asbestos exposure risk. The purpose of this survey is to study the workload of asbestos abatement work by measuring physiological reactions. Physiological strains of 12 male workers and working conditions during asbestos abatements work in two schools were measured in August in 1988 and in 1989. Body weight loss by the work of all workers was measured, and heart rate, rectal temperature and skin temperatures at five sites of some of them were measured every minute.