By Andrew Mackenzie (Associate Director of Strategy and External Relations, The Physiological Society) and Professor Mike Tipton (Chair of the Global Climate and Health Summit 2025; Professor of Human and Applied Physiology, University of Portsmouth)
Launch of Phase One report from the Global Climate and Health Summit
When we hear about climate change, it is often about the forecasts: the temperatures, emissions targets, or economic models. But if we want to understand the real impact of climate change on health, we have to start somewhere else: with the human body.
Heat, air pollution, and poor nutrition aren’t just environmental problems; they are physiological ones. They disrupt our major organs and constrain how we live, work, and survive. Climate change is already challenging the limits of human endurance, and that’s why any effective climate and health plan must be physiology-first.
This idea was at the heart of the Global Climate and Health Summit, which the Physiological Society convened in London and online in July 2025. The goal wasn’t to talk about physiology in isolation, but to connect it to everything else: public health, medicine, law, economics, design, and engineering. The Summit brought those worlds together with more than 500 people from 25 countries to explore how physiological evidence can help society act faster, fairer, and more effectively in response to the health risks of climate change.
Starting with the body
Physiology helps us see climate change through the key lens of what it does to people. It defines the boundaries of human tolerance: the points where exposure to heat, pollution, or undernutrition begins to cause harm, and where survival itself becomes impossible.
These physiological thresholds and limits tell us two things. First, that there are hard limits to adaptation and conditions beyond which no human body can survive. That’s why mitigation, cutting emissions and stabilising the climate is essential. Second, they show us where and when harm to the body starts to occur, long before those limits are reached. Recognising and quantifying these limits and thresholds is vital, especially as they vary between individuals and are influenced by factors such as age, hydration, health, activity level and acclimatisation. This helps us design adaptation that is timely, realistic, humane, and targeted towards those vulnerable groups that are most at risk.
Physiology is the glue that holds the climate and health story together. It turns evidence from many disciplines into a shared understanding of what matters most – the human body’s ability to cope, adapt, and survive. A ‘physiology-first approach’ is about providing the foundation that underpins every perspective on climate and health, the common language linking data, medicine, policy, and lived experience, because every aspect of climate change is ultimately contextualised through its impact on the body.
From discussion to direction
The report we’re launching today ‘Protecting people, shaping policy: Physiology and partnerships at the heart of climate and health’ is the Phase One report from the Global Climate and Health Summit. It marks the first step in turning the ideas gathered from the Summit into a plan of action. It captures the insights and evidence from two days of cross-disciplinary discussion and distils them into four connected, strategic themes that will guide the next phase of work.
- Engaging people focuses on communication and literacy, ensuring individuals, professionals, and communities understand the physiological realities of climate change and have the tools to act.
- Scaling action looks at how to move from small-scale projects to system-wide delivery, connecting innovation, investment, and evidence so that proven, physiology-informed solutions reach those who need them most.
- Delivering accountability explores how physiological evidence can strengthen law and governance, providing credible measures of harm that underpin regulation and drive corporate and political responsibility.
- Defining boundaries calls for physiological evidence to be embedded into planning, regulation, and finance so that decisions reflect what human bodies can actually withstand and adaptation focuses first on those most exposed to risk.
Each theme tackles a different part of the challenge, but together they form a coherent framework: a way to put physiology at the centre of how the world prepares for and responds to climate impacts.
From evidence to impact
This report represents Phase One of that work: using insights from the Summit to identify where physiology, in collaboration with other disciplines, can make a meaningful impact. Phase Two will focus on further cooperation and detailed insights with a series of workshops and roundtable discussions where we’ll work with members, partners, and other experts to turn these themes into specific actions.
That will lead to Phase Three, the Roadmap for Action. The roadmap will set out the Physiological Society’s work programme in this area, rooted in the four themes and built through partnership. It will define where physiology can underpin adaptation, strengthen resilience, and inform mitigation across every sector of climate and health policy.
The Society’s role is to convene. We cannot do this alone. Physiology offers the evidence and consequence, but progress requires collaboration between scientists and policymakers, lawyers and engineers, economists and public-health experts. The body is our common ground, and physiology gives us the context within which we can act together. Working together, across disciplines and across borders, we can turn that understanding into protection, prevention, and progress.
A call to action
The next phase is open to anyone who wants to help shape this work. We’re inviting members, partners and policymakers to take part in the workshops and roundtable discussions that will inform the Roadmap for Action. We want ideas, data, and practical experience from every sector, because climate change doesn’t respect professional boundaries any more than it does national ones.
You can read the full report and register your interest in the Phase Two workshops.
Climate change is already testing, and in some places breaking, the limits of the human body. Physiology shows us where to act and, by working across disciplines and sectors, gives us the means to protect lives, strengthen resilience, and secure a fairer future for all.