The aim of this study was to investigate to what extent venous blood flow from the hand affects evaporative (E) and non-evaporative (R+C) heat losses from the forearm during heat load. Blood flow to and venous flow from the hand were occluded at the wrist for 30 min with cuff (5 cm width) at a pressure of 250 mmHg. Blood circulation in the control hand was not disturbed. After hand vasodilation, forearm skin temperature increased by 3.1℃ on the control side but remained at rest value on the occluded side, with an increased esophageal temperature averaging 0.82℃. Forearm sweat rate at the end of heat load on the control sides was 0.21 units significantly higher than on the occluded side (0.13 units). These results clearly show contributes to the increase in forearm sweat rate and skin temperature after hand vasodilation (mainly through arteriovenous anastomoses: AVA) during heat load.
Preventative measures against heat shock during winter are an urgent problem for the elderly. Heat shock may result in accidental death due to extreme temperature differences within indoor thermal environments. The most common cause of death was from cardiovascular disease or cerebral hemorrhage in the bathroom or restroom. The purpose of this study was to consider prevention against heat shock from the viewpoint of residents. Methods: 1. We surveyed temperature cognition in the restroom and the dressing room. 2. We measured temperature and relative humidity values associated with the restroom during the early mornings, and the dressing room during the nighttime. 3. We surveyed the validity of the effect of the simple thermal insulation on room temperatures. The results were as follows: 1. The temperature cognition survey indicated that residents over 65 years of age were not as sensitive to temperature levels, compared with younger subjects. This was due to the relatively low thermal response of the elderly subjects, compared with the younger subjects, and they stayed in the dressing room for a shorter time period. 2. The measured temperatures were lower than 17°C and temperatures of less than 10°C were experienced more often by the subjects older than 65 years. 3. The simple thermal insulation brought about slight improvements in indoor thermal environments and the thermal comfort of the residents. The installation of the simple thermal insulation induced the residents to spontaneously improve and reform their windows. Our results indicated that recognition of the correct room temperature using thermometers and the simple thermal insulation are valid measures against heat shock from the viewpoint of the residents. It is important to inform residents with concrete information, related to the validity and the cost-effectiveness of preventative measures against heat shock.
Self-assessed survey potentially underestimates the number of person with previous history of heat disorders (HD) when the respondents are not familiar with HD. The purpose of the present study was to clarify whether the studying HD prior to survey affect the number of person with previous history of HD. Ninety collegiate students participated in a self-assessed survey designed to clarify the prevalence of HD experiences from the periods of elementary to high school ages. The survey was carried out before (pre-L) and after (post-L) the HD education which took approximately an hour. Completed survey was received from 83 (92.2%) students. At pre-L 16 students (19.3%) had experienced HD while respondents significantly increased to 31 (37.3%) at post-L (p<0.05). Mean times of HD experience among respondents were 1.31±0.79 (standard deviation) times at pre-L (n=16), and were changed to 1.83±1.18 times at post-L (n=31), but were not significant (p=0.12). Number of respondents who experienced heat exhaustion and heat cramps significantly increased after the education (pre-L; 4, and 1 respondents, post-L; 20 (p<0.05), and 7 (p<0.05) respondents, respectively), while changes in respondents with previous history of heat stroke and unknown were not significant (pre-L; 2, and 9 respondents, post-L; 1, and 3 respondents, respectively). Most of the HD was occurred at junior- to high school when they were engaged in sports club activities. These results suggest that lecture to understand HD prior to survey is needed to comprehend the number of person with previous history of HD.
High NO2 concentrations at night-time at the Tokyo Tower, located in the center of the Tokyo metropolitan area, for the spring to summer seasons and the autumn to early winter seasons of 2009 were analyzed. High potential ozone (PO) concentrations were observed at night-time during the spring to summer seasons, whereas a uniformly low concentration was observed at night-time during the autumn to early winter seasons. Moreover, the average PO concentrations exceeding 80 ppb on average were necessarily observed during the spring to summer seasons. In these seasons, the day-time average PO concentration on the next day exceeded 80 ppb. One of these three cases shows that a heat low was created in the Yamanashi Prefecture during the day-time and a photochemical smog alert was issued, which is supposed to be the transport of pollution from the Tokyo metropolitan area.