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Photo: Moderator Tulip Mazumder; Ibrahima Sy, Minister of Health and Social Action of Senegal;

Dr Sayedur Rahman – Honourable Special Assistant (State Minister), Ministry of Health and Family Welfare, Bangladesh.

Credit: Alice Westerman, The Rockefeller Foundation

Heat is an urgent and multifaceted problem

Rising temperatures are no longer a distant concern. Heat is already disrupting lives: keeping children out of school, reducing wages for outdoor workers, straining hospitals, and even impacting elite sports. The effects are being felt in every corner of the world, with the most vulnerable hit the hardest.

“​​Last year, at least ten countries recorded temperatures of more than 50°C – that’s 122°F. Many dozens more saw daytime overnight temperatures of more than 40°C. These dangerously high temperatures push human health to the brink.” said WMO Deputy Secretary-General Ko Barrett in an opening address, “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.”

Stories shared during the event illustrated this stark reality. Moderator Tulip Mazumdar opened with a personal reflection, recalling the summer of 2022 when, caring for her newborn during London’s first 40°C day, she realized how critical access to cooling really is. “I could order an air conditioner with a click,” she said. “Most people don’t have that choice.” 

The event gave voice to many living without that safety net, from farmers and factory workers to those responding on the frontlines of public health. Speakers from Senegal, Bangladesh, Brazil, and Spain described the concrete impacts of extreme heat in their countries: children fainting in classrooms, lost livelihoods, and communities struggling to cope. 

Reema Nanavaty of India’s Self Employed Women’s Association (SEWA) described how informal women workers, from salt pan labourers to street vendors, are improvising to survive in unbearable heat. “For our members, innovation is not a luxury—it’s survival,” she said. But the impact runs deeper. “We don’t even have data on what this heat is doing to their bodies.” Her call for climate-linked insurance and accessible public health data was echoed by Petra Khoury of the International Federation Red Cross Red Crescent Societies, who noted that early warning systems only work if people know how, and are able, to act on them.

Senegal’s Minister of Health Ibrahima Sy explained how local data on temperature-related mortality helped build political momentum for early warning systems and long-term adaptation. “If we can’t measure it,” he said, “we can’t prepare for it.”

Action must be coordinated and scaled

This is not just about weather. It’s about people, and it’s about systems: how we plan our cities, prepare our health systems, and protect those at risk. Extreme heat has become a defining challenge for public health, cutting across borders and politics. It demands collaboration between health, meteorological, and many other sectors.

Several panellists highlighted the power of evidence-based interventions. Dr. Abderrezak Bouchama, a critical care specialist with decades of experience treating pilgrims in Mecca, reminded the audience that heatstroke can turn deadly in minutes. “By the time many patients reach the hospital, they’re already unconscious,” he said. “We need better awareness, better training, and faster action.” Meanwhile, Olympic physician Dr. Jane Thornton noted that even elite athletes are no longer safe from rising temperatures. “This isn’t just about performance—it’s about health. And these risks are growing.”

The event also featured a recorded message from Freetown Mayor Yvonne Aki-Sawyerr and presentations from Southeast Asia and Africa, highlighting local innovation and growing regional momentum. 

Jason Lee, Associate Professor at the National University of Singapore and chair of GHHIN’s new regional hub in Southeast Asia, urged the audience to reject complacency. “In Southeast Asia, people say we’re used to the heat—but that’s exactly the danger,” he warned. “We’ve normalized what’s no longer safe.” He stressed that solutions need to speak to people’s lived realities: “If you’re telling someone to stay home, but they need to work to eat—that message will never land.”

“Extreme heat is no longer a distant or seasonal concern—it’s a daily reality for millions.” said Joy Shumake-Guillemot, lead of the WHO-WMO Climate and Health Joint Programme and GHHIN co-lead, following the event, “Our Network is connecting science, policy, and action so that no community is left behind in the race to adapt to climate change that will continue to worsen extreme heat for years to come. This is not just a climate issue, it’s a public health emergency.” 

“Heat kills. It doesn’t have to,” added Diarmid Campbell-Lendrum, Climate Change and Health Unit Lead at the World Health Organization, “There’s a great deal we can do—and we’re absolutely committed to working with all partners to reach the most vulnerable.”

What’s next?

GHHIN is working with a wide range of partners to build a global community around extreme heat. That means sharing knowledge, supporting regional hubs, and creating the tools needed to turn science into action. Heat health early warning systems, improved public communication, and better access to climate data for health officials is just the start. 

Event co-hosts Wellcome and the Rockefeller Foundation announced a new partnership to accelerate efforts to help countries build climate-informed health systems. Backed by US$11.6 million in initial funding, the partnership will advance the work of the WHO-WMO Joint Programme and its partners to support and scale up climate services for health around the world, with GHHIN leading the charge on extreme heat. 

As part of this global movement, the side event helped set the stage for what’s next:

• Ensuring extreme heat is addressed in global climate and health goals; including the 2025 G20 Summit and UNFCCC COP30.

• Scaling Research and innovation to deploy what works to protect the most vulnerable

• Expanding partnerships and investments in integrated  local planning and heat governance;

The Network thanks its partners, speakers, and participants for joining this call to action. Extreme heat is no longer a silent killer. It is a global threat that we can prepare for and protect against, but only if we act together.

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