Comment: 26 pages, 2 figuresThis study investigates the impact of the 2018 summer heat wave on urban mobility in Seoul and the role of economic complexity in the region's resilience. Findings from subway and mobile phone data indicate a significant decrease in the floating population during extreme heat wave, underscoring the thermal vulnerability of urban areas. However, urban regions with higher complexity demonstrate resilience, attracting more visitors despite high temperatures. Our results suggest the centrality of economic complexity in urban resilience against climate-induced stressors. Additionally, it implies that high-complexity small businesses' clusters can serve as focal points for sustaining urban vitality in the face of thermal shocks within city. In the long run perspective, our results imply the possibility that people are more concentrated in high complexity region in the era of global warming.