My research has two main objectives. One is to clarify the relation between the thermal physiological state of humans and humans’ thermal perceptions or thermal risk. The other objective is to evaluate humans’ thermal perception and thermal risk by developing suitable human thermal models to predict the thermal state of humans. On the basis of these researches, I intend to develop a reasonable thermal environment for developing a sustainable society in the future. Humans’ thermal risk and thermal perception are affected by many factors such as thermal radiation (e.g., solar radiation), humidity, clothing, air velocity, activity, and air temperature. On the basis of additional knowledge on humans’ thermal state involving thermal comfort (e.g., mean skin temperature of 33.5 ºC for a sedentary posture) and the combined effect of the abovementioned factors, we intend to develop highly reasonable systems for heating and refrigerating, which would reduce environmental loads.
  Thus far, on the basis of experiments conducted using human subjects in up/down, right/left, or front/back asymmetric thermal environments, our group elucidated the following local characteristics in the head and feet areas. Because of the high heat generation rate and high skin temperature in the head area, thermal discomfort caused by heat was closely related to the decrease in the heat dissipation rate from the head area. Because of a variable local skin temperature, thermal discomfort caused by feeling cold was closely related to the fall in the local skin temperature. On the basis of the experimental data, a comfort equation by local skin temperatures and local sensible heat losses was proposed for a human in a sitting posture in a nonuniform thermal environment. In addition, our group also proposed a new human thermal model. The model considers (1) the redistribution of body heat by blood perfusion, (2) the nonuniform properties of tissues, and (3) heat exchange by respiration. Three-dimensional (3-D) temperature fields and 3-D heat transfer inside the human body are analyzed using local inputs of air temperature, thermal radiation, humidity, clothing, air velocity, and metabolic heat production. On the basis of these outcomes, I intend to develop a new analytical tool to simulate a human-clothing-environment system on a PC; it would be possible to use this tool under both steady conditions in the sitting posture and nonsteady conditions during various activities.

     By utilizing the functions of clothing and the adaptation ability of the human body, I intend to achieve a safe and satisfactory living environment for a sustainable society in the future. In most cases, clothing is effective in controlling the microclimate around humans. However, existing clothing cannot control the microclimate around an area that is not covered by clothes. Then, it is difficult to improve the microclimate around the head area particularly in hot environments. Because of these reasons, I feel the necessity to appreciate the thermal characteristics and limitations of existing clothing and the adaptation ability of the human body. On the basis of the result of this study, I intend to discover new possibilities for clothing and the adaptation ability of the human body. Simultaneously, in the Young Researchers Empowerment Project carried out at Shinshu University, I desire to obtain a broad viewpoint that includes tactile impressions, mobility, economical efficiency, and the human-clothing-environment system. Then, in the near future, I intend to propose new values or concepts for clothing, textile, and so on, for the development of a sustainable society.