Urban heat is a public health issue: Foshan chikungunya outbreak exposes a governance gap between urban cooling, vector control, and health equity

Source abstract

Rising urban heat poses an urgent threat to public health. The extreme heat in cities causes heat-related illnesses and accelerates heat-sensitive infectious diseases. Beyond heat-related illness, urban heat can intensify the transmission risk of heat-sensitive vector-borne diseases. Chikungunya fever, a mosquito-borne viral disease that causes fever and severe joint pain, is transmitted mainly by Aedes mosquitoes. The 2025 chikungunya outbreak in Foshan, China, provides an important case through which to examine how extreme heat, humidity, urban microclimates, and social vulnerability can converge to produce compound climate-health risk. However, current adaptation solutions remain fragmented. This fragmentation increases the risk of maladaptation, especially when cooling measures are pursued without adequate drainage, maintenance, or mosquito-habitat management. In response, this commentary proposes a health-first urban cooling agenda that integrates thermal mitigation, vector-safe environmental design, and equity-oriented protection across short, medium, and long-term timeframes. Rather than treating heat adaptation and infectious-disease control as parallel agendas, cities should approach them as interdependent forms of public-health infrastructure. This integrated perspective is essential for strengthening urban resilience under intensifying climate extremes.