Date of Degree


Document Type


Degree Name



Liberal Studies


Deborah Balk


Heatstroke, Demography, Japan, Climate Change, Spatial Analysis


This master’s thesis attempts to discover demographic and spatial disparities in heatstroke deaths in Japan. The first part of analyses was conducted by demographic methods, which utilizes heatstroke deaths data classified under the ICD-10 code from 1995 to 2017. I found that males had more deaths than females during the study period and that the elderly population of both genders had significantly higher number of deaths. In addition, the study examined the probability of surviving and life expectancy among the elderly population when eliminating heatstroke deaths, improvement in these two variables was observed however remained small, as the number of heatstroke deaths has been small, compared to other major diseases.

The second part of the study is spatial analyses of heatstroke deaths by prefecture and patients in 23 special wards as well as Osaka City. In this part, the study used prefectural heatstroke deaths data from 2013 to 2017, during which the total number of deaths was concentrated in prefectures with large populations such as Tokyo and Osaka Prefecture. However, the crude death rate (CDR) for both genders was higher in other prefectures; with Okinawa Prefecture having the highest CDR among elderly males while Toyama Prefecture having the highest CDR among elderly females.

Through reviewing several researches on how different elderly males and females had experienced heatstroke, the study also identified spatial variations in heatstroke occurrence between males and females: males experiencing heatstroke the most in the bedroom while females experiencing it the most in the kitchen. This difference suggests that heatstroke may have occurred more on a particular gender depending on their traditional gender roles within households. Lastly, the vulnerability assessment on heatstroke risk in Tokyo Metropolitan area and Osaka City was conducted by using the several human factors of heatstroke such as the elderly population. The result was that several wards in both study areas had much higher vulnerability compared to other wards, which indicates the spatial disparities of heatstroke risks within the two major metropolitan areas of Japan.