The heat wave is already a serious natural disaster that has been selected as a major threat to the world by 2020 at the World Economic Forum. As a result, a amount of public funds have been invested for the purpose of countering the heat wave, but it is not reasonable since it has not been closely reviewed for its effectiveness. In this study, Daegu Metropolitan City was set as a pilot system, and among the various heat wave measures, especially focused on the heat wave vulnerable class support project, we analysed using System Dynamic method how the pattern of occurrence of heat sickness, which can be seen as the effect of the policy, changes as the rate of support for the vulnerable class fluctuates. In addition, in terms of the complex prescription of the policy, we also examined the effect of the mixed prescription for the support policies for the vulnerable groups and eco-friendly policies. As a result of the analysis, strengthening the support for the vulnerable groups was confirmed to reduce the number of patients with thermal diseases, and to increase the GRDP and revitalize the local economy. High synergies are expected when supporting eco-friendly policies such as fossil energy reduction along with supporting the vulnerable groups in the heat wave. It is expected that the results of this study will be utilized as a basis for determining the priority of the heat wave countermeasures, thereby contributing to improving the efficiency of the heat wave countermeasures.