2024 was the hottest year ever recorded. For Asia and the Pacific, the implications were especially stark. Temperatures in parts of South and Southeast Asia reached 53°C, and between December 2024 and February 2025, 6 of the 11 global cities that experienced prolonged extreme heat – lasting 30 days or more – were in this region. This isn’t a temporary anomaly. It is a glimpse into a future that has already arrived.

The climate crisis is a health crisis, particularly in urban settings. This region’s cities, home to hundreds of millions, are grappling with the growing intensity and frequency of heatwaves, deteriorating air quality and the increasing spread of climate-sensitive diseases such as dengue and malaria. These pressures are not only undermining the resilience of health systems but also deepening existing vulnerabilities for those already on the margins.

Recently at a consultation in Bangkok organized by Climate Resilience for All, I heard from women informal workers in Thailand who shared what it means to endure extreme heat without the option to retreat. One woman said that her need to earn a daily income “burns brighter than the sun.” Her words capture the cruel paradox many people face: the very conditions that threaten their health are the ones they must work through just to survive. From respiratory and cardiovascular issues to heightened risk of miscarriage, the health effects of extreme heat are wide-ranging and deeply personal.

The individual stories of the informal workers reflect a broader and deeply worrying pattern across the region. Approximately 90 percent of the population in Asia and the Pacific regularly breathes air deemed unsafe by World Health Organization (WHO) standards. More than 500 million people lack access to basic water supplies, and the region is projected to experience a 5 to 20 percent increase in drought conditions by the end of this century. At the same time, 70 percent of the global population vulnerable to sea-level rise lives in Asia and the Pacific, which is also home to six of the world’s largest coastal megacities. Compounding this, the region faces an average of six natural disasters annually – three times the rate seen in sub-Saharan Africa. In 2022 alone, extreme weather events led to the deaths of 7,500 people, affected 64 million more and caused an estimated US$57 billion in economic damages. Warmer temperatures and disrupted rainfall are also driving the spread of vector-borne diseases such as dengue and malaria, which are increasingly appearing in areas previously considered low-risk – including urban centres – placing new burdens on already overstretched health services.

This intersection of climate, environment and health demands urgent action. Yet, health often remains under-prioritized in climate adaptation efforts. Less than one percent of global climate finance is allocated toward health protection, even as cities struggle to cope with the growing burden of climate-related health threats. 

At UNDP, we are committed to addressing this gap. In 2024, we supported 72 health projects across the region, including a growing number focused specifically on the climate-health nexus. Through partnerships with the Green Climate Fund, the Global Environment Facility, the Clean Air Fund, the Government of Japan, the Global Fund to Fight AIDS, Tuberculosis and Malaria, Gavi and others, we are helping countries build more resilient and inclusive health systems. We are also exploring new financing models that connect climate investment with health outcomes, particularly in countries where climate threats and development needs converge most acutely.

But we know that the scale of the challenge calls for a broader shift. Cities must plan for and invest in health systems that can anticipate and respond to climate shocks. This means integrating health into urban governance, expanding access to early warning systems and strengthening primary care that can operate under extreme conditions. It also requires centering the voices and experiences of those most at risk – women, informal workers, youth, persons with disabilities – so that policies and programmes reflect the realities on the ground.

Asia and the Pacific stand at a critical juncture. This region is on the frontline of climate impacts, but it is also rich in innovation, community leadership and resilience. The decisions we make now – about where and how we invest, and who we prioritize – will determine whether our cities become places of safety and health, or hotspots of inequality and risk. Because in a region where the sun burns hotter each year, resilience must burn brighter still.