Extreme Heat Crisis Spurs Global Action as Deaths Mount and Wildfires Spread

As the planet marked the first anniversary of the UN Secretary-General’s Call to Action on Extreme Heat on 25 July 2025, dangerous heatwaves scorched vast regions across the globe, from North America to the Middle East and Europe, exposing billions of people to health risks, livelihood disruptions, and worsening climate hazards. The escalating crisis, unfolding amid record-breaking temperatures, underscored the urgent need for international coordination, early warning systems, and comprehensive heat-health action plans.

To commemorate the milestone and elevate heat resilience, 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 suite of new global resources to support better heat governance, data-driven decision-making, and targeted protection for vulnerable populations.

A Heatwave Season of Devastation

In recent weeks, over 20 million people in the southeastern United States were placed under “extreme heat risk” warnings by the U.S. National Weather Service, with “feels-like” heat index values ranging between 110–115°F (43–46°C). The prolonged heatwave is expected to last into early August.

Meanwhile, extreme heat has gripped North Africa and the Middle East, crippling electricity and water supply systems in Iran. Across the Mediterranean and Balkans, the third heatwave of the summer ignited wildfires, devastated agriculture, and shuttered tourist landmarks in Greece, Italy, Spain, Türkiye, and Cyprus. Cyprus recorded its hottest July day on record at 44.6°C, while some regions in Türkiye neared 50°C.

Scandinavian nations — typically considered temperate — were not spared. Finland experienced more than 15 consecutive days of above 30°C temperatures, with Norway and Sweden facing elevated forest fire risks due to the heat.

The European Centre for Medium-Range Weather Forecasts (ECMWF) and Copernicus Climate Change Service confirmed that June 2025 was Europe’s hottest on record, driven in part by unprecedented sea surface temperatures in the western Mediterranean.

Globally, it was the third warmest June on record, according to NOAA and EU climate agencies, adding to the mounting evidence of a climate emergency.

“Silent Killer” with Deadly Impact

“Extreme heat is sometimes called the silent killer, but with today’s science, data and technologies, silence is no longer an excuse,” stated WMO Deputy Secretary-General Ko Barrett.

Between 2000 and 2019, modelled estimates suggest that 489,000 people died annually due to heat-related causes, with Asia accounting for 45% and Europe 36% of those deaths. Actual figures are believed to be higher due to underreporting and inconsistent diagnostics.

The threat is both immediate and growing. Without urgent adaptation and public health interventions, the toll will rise sharply with each passing year.

A Global Response Framework

In response, WMO and ten other UN entities are rallying behind the UN Secretary-General’s four-pillar Call to Action on Extreme Heat:

1. Caring for the most vulnerable, including the elderly, young children, and people with pre-existing health conditions.

2. Protecting workers and populations exposed to heat stress.

3. Boosting societal and economic resilience through improved data, early warning, and infrastructure.

4. Limiting global temperature rise to 1.5°C under the Paris Agreement.

WMO, under the Early Warnings for All initiative, is advancing efforts to scale up heat early warning systems (HEWS) worldwide. Timely alerts that include clear, actionable guidance on heat protection measures could save thousands of lives annually.

A joint WHO-WMO estimate suggests that implementing HEWS in just 57 countries could prevent over 98,000 deaths every year.

New Tools and Resources Launched

To guide governments and institutions, GHHIN, UNDRR, and WMO released three new key resources:

1. Stocktake Report: Heat Action Across UN Entities

This first-of-its-kind report maps existing efforts, identifies collaboration gaps, and recommends strategies to support the Secretary-General’s heat resilience agenda through improved governance and inter-agency coordination.

2. Assessment of Heat Action Plans

Drawing on six country-level evaluations (Australia, Canada, France, India, the UK, and the U.S.), this synthesis provides a global framework for effective heat planning — highlighting best practices, persistent barriers, and success metrics.

3. Narrative Case Studies on Heat Resilience

Twelve case studies from Argentina, Australia, Bangladesh, Canada, Ecuador, Egypt, France, India, Senegal, South Korea, the UK, and the U.S. illustrate varied governance approaches, partnerships, and innovations. These stories offer insights into how diverse societies are responding to escalating heat threats with local and national strategies.

Partnerships Fueling the Push Forward

The growing focus on heat is backed by substantial financial support. The Joint Climate and Health Office, a partnership between WHO and WMO, is receiving a boost from the Rockefeller Foundation and Wellcome Trust, which have mobilized US$11.5 million in funding focused on extreme heat resilience.

“The heat crisis is no longer seasonal or regional — it’s a daily reality for millions,” said Joy Shumake-Guillemot, WHO-WMO Climate and Health lead and GHHIN co-lead. “This is not just a climate issue; it’s a public health emergency. Our Network is working to ensure no community is left behind.”

The Way Forward: Heat as a Central Climate Challenge

Extreme heat is a universal threat that touches on health, equity, labor rights, urban planning, and energy systems. As climate change intensifies, so too must the global response — rooted in science, solidarity, and swift action.

With temperatures rising and lives at stake, the world cannot afford to ignore the deadly impact of heat. The anniversary of the Call to Action is not merely a commemoration — it is a clarion call for every country to integrate heat preparedness into their climate, health, and disaster risk agendas.