In the summer of 2023, heatwaves became quite prominent in the south of Europe. Due to the extreme heat, the health of those citizens was affected. The Netherlands Meteorological Institute predicts an increase in heatwaves in the future for the Netherlands as well. The main research question is how to propose a strategy for a liveable environment by designing public spaces while mitigating heat stress for vulnerable target groups in the context of Bospolder Tussendijken in Rotterdam. This research questions also how a reproducible tool could help identify heat stress and test design interventions in Dutch cities. The research included a literature review, expert consultations, scenario planning, modelling of the urban environment and mapping techniques. Comparing the heat stress software reproducibility, computation time, possibility to test design interventions and the scale of modelling were important. Improvements in the reproducibility of the PET map of Koopmans et al. (2020) are made by creating an open-accessible QGIS plugin applicable to Dutch cities. This helps urban designers to indicate and test their design interventions. Refinement of the wind calculation contributed to speeding up calculation times of the wind for neighbourhood and city scale areas. Future research should focus on some refinement in PET calibration to work properly, and advanced wind modelling is required for urban design practices. The application in the Rotterdam test case study emphasizes the importance of maintaining liveability now and in the future. By enhancing social liveability and physical liveability within a network of heat-mitigating interventions liveability is guaranteed. By revealing the vulnerable groups and their social interactions on a summer day, the most frequently used routes are qualified for refurbishment. Based on the current quality of social space and walkable environment, ownership and degree of open space on the street level, the interventions are chosen for the situation. The research emphasized the importance of identifying heat stress in public spaces and the need for urgent action to maintain the quality of life in the future. By integrating informed strategies from multiple fields like Geomatics and Urbanism a climate-adaptive and healthy environment can take shape.