This paper explores tactical urbanism as a bottom-up approach to improving urban microclimates and public health in cities affected by climate change. Through literature review, case studies, and evaluation criteria, it examines community-led interventions such as afforestation projects, pop-up streets, and temporary parks. Findings show that these strategies enhance shading, airflow, and evapotranspiration while strengthening social resilience and local ownership of public spaces. The study proposes a framework to integrate tactical interventions into formal planning, positioning them as effective complements to conventional top-down urban climate adaptation.