UN Marks Extreme Heat Call Anniversary Amid Global Heatwaves and Health Risks

As the world grapples with record-breaking temperatures and widespread heat-related emergencies, the United Nations commemorated the first anniversary of the Secretary-General’s Call to Action on Extreme Heat on 25 July. This milestone comes amid intensifying global heatwaves, from the Americas and Europe to North Africa and Asia, highlighting the urgent need for heat-risk governance, early warning systems, and coordinated health-focused climate action.

To mark the occasion, the Global Heat Health Information Network (GHHIN), in partnership with the World Meteorological Organization (WMO) and the UN Office for Disaster Risk Reduction (UNDRR), launched a series of knowledge resources under the initiative Supporting Extreme Heat Risk Governance. These tools are designed to help nations confront and manage the growing public health and economic risks posed by extreme heat.

“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,” said WMO Deputy Secretary-General Ko Barrett.

A Global Wake-Up Call as Heat Grips the Planet

As of 24 July, nearly 100 million Americans were under heat advisories for what was classified as “dangerous” heat levels. Across the globe, heatwaves wreaked havoc:

• In Iran, power and water supplies were disrupted.

• The Mediterranean and Balkans faced their third wave of the summer, forcing closures of tourist sites, halting outdoor labor and agricultural activities, and igniting wildfires that have claimed lives and worsened air quality.

• Europe registered its hottest June on record, with very strong heat stress conditions across the western and southern regions, driven by high sea surface temperatures in the Mediterranean.

• Globally, it was the third hottest June on record, according to NOAA and Copernicus Climate Change Service.

These extreme weather events reinforce the need for robust early-warning systems and heat-health preparedness strategies — the core message behind the UN’s Call to Action.

Extreme Heat: A Public Health Emergency

Heatwaves are already responsible for a significant but underreported number of deaths. Between 2000 and 2019, an estimated 489,000 people died annually from heat-related causes — with 45% of deaths in Asia and 36% in Europe. Health officials say the actual toll may be higher due to underdiagnosis and underreporting.

“Extreme heat is no longer a distant or seasonal concern—it’s a daily reality for millions,” said Dr. Joy Shumake-Guillemot, head of the WHO-WMO Joint Climate and Health Office and co-lead of GHHIN. “This is not just a climate issue — it’s a public health emergency.”

In response, the Early Warnings for All initiative, supported by WMO, is scaling up efforts to ensure at-risk populations receive timely alerts with actionable guidance. The WHO-WMO collaboration estimates that expanding heat-health early warning systems to just 57 countries could save over 98,000 lives per year.

Global Governance and Knowledge Sharing

The new resources launched by GHHIN, WMO, and UNDRR aim to address governance gaps and build local capacity. The suite includes:

1. Stocktake Report: Heat Action Across UN and International Bodies

For the first time, this report maps out how different UN entities and global organizations are managing extreme heat, highlighting coordination challenges and opportunities for integrated governance.

2. Assessment of Heat Action Plans

This synthesis evaluates best practices and persistent challenges from national heat plans across six countries: Australia, Canada, France, India, the UK, and the US. It offers a structured framework for improving resilience and public response.

3. Narrative Case Studies on Heat Resilience

A deep dive into the real-world experiences of 12 countries — including Argentina, Bangladesh, Egypt, Ecuador, Senegal, and South Korea — the case studies explore governance models, partnerships, and innovations in extreme heat management. They showcase diverse contexts and evolving strategies to adapt to increasingly hazardous temperatures.

Four Pillars of the UN’s Heat Response Agenda

The Call to Action on Extreme Heat, supported by 10 UN agencies including WMO and WHO, focuses on four key areas:

• Caring for the vulnerable: Prioritizing at-risk populations such as children, the elderly, and outdoor workers.

• Protecting workers: Developing occupational safety standards and adapting work schedules.

• Boosting economic and societal resilience: Leveraging science and data to inform planning and infrastructure.

• Limiting global temperature rise to 1.5°C: The ultimate long-term solution to curbing the frequency and severity of extreme heat events.

The program is backed by $11.5 million in new support from the Rockefeller Foundation and Wellcome, aimed at bolstering local capacity and developing scalable solutions.

Preparing for a Hotter Future

With climate change expected to intensify the frequency and severity of heatwaves in the coming decades, the anniversary of the Call to Action on Extreme Heat is both a somber reminder and a call for renewed urgency.

“Our Network is connecting science, policy, and action so that no community is left behind in the race to adapt,” said Dr. Shumake-Guillemot.

As 2025’s COP30 in Belém, Brazil approaches, global attention is expected to shift even more toward adaptation and health-based climate action. Extreme heat will remain a key focus, not only as a symptom of climate change but as a direct and growing threat to human health, economic productivity, and global stability.