Extreme Heat: A Global Public Health Emergency Demanding Urgent Action
The First Anniversary of a Global Wake-Up Call
One year after the United Nations Secretary-General’s Call to Action on Extreme Heat (July 25, 2024), the climate emergency continues to escalate.
The growing intensity and frequency of extreme heat events are leaving deadly footprints across continents—from record-breaking temperatures in Asia and Europe to wildfires in the Mediterranean and heat emergencies in North America.
The Global Heat Health Information Network (GHHIN), in partnership with the World Meteorological Organization (WMO) and the UN Office for Disaster Risk Reduction (UNDRR), has launched a coordinated response to strengthen heat risk governance.
These efforts come amid a stark reminder: extreme heat is no longer a distant threat—it’s a daily reality.
Heatwaves Across Continents: A Summer of Records and Ruin
From Japan's all-time high of 41.2°C to Türkiye’s scorching 50.5°C, the planet is reeling under temperatures once considered implausible. In the Republic of Korea and Japan, dangerously high overnight temperatures are compounding the risk to human health.
The Southeastern USA, enduring one of its most prolonged heatwaves, recorded a “feel-like” heat index of 43–46°C, with warnings extending into August.
In North Africa and the Middle East, particularly Iran, heat has disrupted basic infrastructure—triggering water and power shortages. The Mediterranean and Balkan regions face their third heatwave of the season, compounding strain on outdoor workers and agricultural systems.
Wildfires—intensified by dry conditions and relentless heat—have devastated landscapes in Cyprus, Greece, and Türkiye, resulting in casualties, displacement, and air quality deterioration.
Even Scandinavia, usually shielded from such extremes, is feeling the burn. Finland experienced over 15 days above 30°C, with Norway and Sweden issuing forest fire warnings. Across Western and Southern Europe, June 2025 was the hottest on record, aggravated by unusually warm sea surface temperatures.
A Silent Killer That Can No Longer Be Ignored
“Extreme heat is sometimes called the silent killer, but with today’s science, data and technologies, silence is no longer an excuse. Every single death from extreme heat is preventable,” emphasized WMO Deputy Secretary-General Ko Barrett.
Modelled estimates show nearly 489,000 heat-related deaths per year between 2000 and 2019—45% in Asia and 36% in Europe. Yet, these figures likely understate the true toll, as underreporting of heat-related illnesses and fatalities remains widespread.
Global Collaboration: From Awareness to Action
In response to the Secretary-General’s Call to Action, the WMO and its Members are expanding heat early warning systems under the Early Warnings for All initiative. These systems aim to equip vulnerable populations with real-time alerts, guidance on protective steps, and access to life-saving resources.
Four pillars define this global agenda:
Caring for vulnerable populations
Protecting workers
Strengthening economic and societal resilience
Limiting global warming to 1.5°C
According to WMO-WHO estimates, scaling up heat-health warning systems across 57 countries could save over 98,000 lives annually.
Connecting Science, Policy, and People
“Extreme heat is no longer a seasonal concern—it’s a public health emergency, affecting millions daily,” said Joy Shumake-Guillemot, co-lead of the WHO-WMO Climate and Health Joint Programme and GHHIN. She emphasized the urgent need to “connect science, policy, and action” to ensure no community is left behind.
This vision is now supported by a $11.5 million partnership between the Rockefeller Foundation and Wellcome, targeted specifically at extreme heat adaptation.
New Tools to Govern Heat Risks More Effectively
To mark the anniversary of the Call to Action, GHHIN, WMO and UNDRR have released a suite of new resources to bolster heat risk governance:
Stocktake Report: A first-of-its-kind review of how UN entities and international organizations are managing extreme heat, offering opportunities for enhanced collaboration.
Assessment of Heat Action Plans: Drawing from the experiences of six countries—Australia, Canada, France, India, the UK, and the USA—this synthesis outlines best practices and challenges, setting a framework for global heat resilience.
Narrative Case Studies: Documenting 12 countries’ efforts—including Bangladesh, Senegal, and Ecuador—these stories reveal diverse strategies and innovations to tackle the realities of rising temperatures.
Conclusion: Heat is Here—Now What?
The unprecedented nature of current heat events is no longer anecdotal—it’s supported by robust global data. Whether it’s tourist attractions closing in Spain, infrastructure breaking down in Iran, or wildfires forcing mass evacuations in the Mediterranean, the impacts are deeply human and deeply preventable.
The science is clear, the data is available, and now, so are the governance tools. What remains is the political will and investment needed to implement solutions equitably across borders.
As Ko Barrett aptly noted, “With today’s science, silence is no longer an excuse.” The time to act boldly, collaboratively, and urgently—is now.
