Driven by climate change and rapid urbanisation, coping with concurrent heatwaves and ozone pollution in megacities of East and Southeast Asia is an urgent public health and environmental challenge. The interplay between extreme heat and high ozone levels creates a compounded health risk, highlighting the necessity to formulate effective response actions that address both environmental stressors simultaneously. This research focuses on a few major megacities in this region, including Beijing/Shanghai (China), Tokyo (Japan), Seoul (South Korea), Bangkok (Thailand), and Kuala Lumpur (Malaysia), which are highly urbanised and densely populated yet have significant potential for addressing concurrent heatwaves and ozone pollution. However, disparities in resources, infrastructure, and socio-economic conditions exist amongst them, affecting their capacity to implement effective mitigation and adaptation measures. By analysing past heatwaves and ozone pollution events in these cities, the study aims to identify gaps in current mitigation efforts, highlight effective practices, and offer insights for future public health strategies and urban planning to better cope with the dual challenge of rising climate and air pollution. Results of this work will be disseminated to the public, policy makers and stakeholders via various public engagement events to improve public attention to the issue and better manage the problem.