A new report from the ASEAN Centre for Energy (ACE), titled Roadmap for Passive Cooling Protection Against Extreme Heat in ASEAN, warns that Bangkok could become the hottest major city in ASEAN by 2050.

According to the report, Bangkok’s average daily maximum temperature is projected to reach 38.1°C by mid-century, while the number of extreme heat days—defined as temperatures exceeding 35°C—could increase from approximately 45 days per year today to around 120 days annually.

The study highlights climate change and rapid urbanization as key drivers of rising temperatures and intensified urban heat island effects across Southeast Asia. As extreme heat events become more frequent, demand for cooling solutions in commercial buildings, industrial facilities, healthcare institutions, cleanrooms, and data centers is expected to grow significantly.

ACE emphasizes the importance of passive cooling strategies, including natural ventilation, shading, reflective roofing materials, and high-performance glazing. These measures could reduce building cooling energy consumption by 35% to 70%, helping cities improve energy efficiency while enhancing climate resilience.

Industry experts also call for stronger building regulations, greater adoption of sustainable construction practices, and increased investment in energy-efficient HVAC technologies to address the region’s long-term cooling challenges.

As ASEAN continues to pursue green building development and low-carbon growth, advanced HVAC&R systems, sustainable cooling technologies, and climate-responsive building solutions are expected to play an increasingly important role in shaping the region’s future.