Five ways the UK can prepare for a hotter, riskier future

Extreme heat in the UK is no longer a distant or seasonal issue. It’s a growing national risk.

When the UK hit over 40°C in 2022, nearly 3,000 excess deaths (deaths surplus to what’s normally expected for that time of year) were recorded in England alone. Train lines buckled, hospitals overheated and fire services were overwhelmed.

Globally, extreme heat is one of the deadliest climate hazards, causing an estimated 489,000 deaths annually. But these death are preventable.

Our recent study in the journal Earth’s Future and other reports on the subject say the same thing: that the UK is not ready for a future of extreme heat. The UK’s efforts still focus largely on immediate health consequences, rather than the risks that unfold more widely on education, supply chain, infrastructure and the economy.

Our analysis of the 2022 heatwave reveals a web of cascading effects: wildfires, power failures, water shortages, overwhelmed emergency services and serious disruption to transport. For example, Network Rail, the state-owned company responsible for Britain’s railway tracks and stations, spent £51 million on compensation due to heat-related disruptions between 2016 and 2021.

Consequences extend globally. The humanitarian aid charity Unicef reported that in 2024, 242 million students were affected by heat-related school closures, and US$863 billion (£643 billion) in workforce income losses were recorded in 2022 due to reduced productivity.

Here are five key actions the UK should prioritise:

1. Retrofit buildings to handle heat

UK homes are built to retain heat, a dangerous liability during hotter summers. Right now, more than half of homes in the UK can get uncomfortably hot during heatwaves. If the planet warms by about 2°C on average (a level many scientists warn could be reached this century), that number could jump to nine out of every ten homes.

Existing buildings, many of which are among the oldest in Europe, are not covered by current overheating regulations. A national retrofit strategy urgently needs to include passive cooling, such as ventilation, shading and reflective materials that improve buildings in energy-efficient ways as standard.

Other countries are already taking proactive steps. In Barcelona, for example, public schools are being converted into “climate shelters” with fans, shade, and water access so they can protect people during extreme heat. The UK could adopt similar measures – turning schools, libraries and community centres into safe, cool spaces to help residents cope with increasingly severe heatwaves.

Read more: Three ingenious ways architects are designing buildings to stay cool in a heatwave without air conditioning

2. Make public communication more effective

Heat warnings alone won’t change behaviour. Many people remain unaware that heat can be fatal, especially for the most vulnerable, such as children, older people and people with chronic illnesses. Public messaging must be practical and timely, with advice tailored to specific contexts (such as care homes, schools or outdoor workplaces). Advice also needs to encourage people to make healthier choices, while ensuring that better options are affordable and accessible to everyone.

One example comes from Ahmedabad, India, where heat-related deaths have dropped sharply since its Heat Action Plan began. The programme works because it targets vulnerable groups, trains health workers, provides shade and water for outdoor labourers and schoolchildren, and warns residents before dangerous heat hits. A simple “heat rating” in forecasts, backed by text alerts and local media, helps people take timely action.

Our work with Shade the UK, an NGO dedicated to adapting the UK’s built environment and public spaces to climate change, and Love Design Studio, a sustainability consultancy, shows that implementing a simple heat metric (similar to existing energy performance certificates) could empower residents and property owners to act. The metric would show the level of heat risk in a property and outline practical measures to make it cooler.

3. Focus on the most vulnerable

Heat effects are uneven. In 2022, central London boroughs such as Hackney, Tower Hamlets and Islington faced notably higher heat exposure (consistent with urban heat island effects that can elevate temperatures by 5–6°C compared to less dense areas) driven by their high building density and limited green space. Vulnerable populations, including older adults and low-income residents, face a higher risk but have fewer resources to cope.

By mapping vulnerability hotspots (creating maps that show where heat risk and social vulnerability overlap), authorities and volunteer groups can more easily deliver targeted local responses, such as providing access to cool spaces and carrying out welfare checks for vulnerable people during heatwaves.

London has already begun producing such heat risk and vulnerability maps. Some boroughs (such as Tower Hamlets) have acted on them, for example, by identifying schools and homes at greatest risk, but these maps need to become consistent, regularly updated and directly tied to local response plans.

Read more: Five ways to keep towns cool in a heatwave

4. Improve coordination

One of the clearest findings from our latest research is that no single agency had a full view of the risks during the 2022 heatwave. Emergency responders focused on immediate incidents, while local authorities and national agencies operated in parallel, not in partnership.

Insights from our policy roundtable, held in London on February 11 with senior representatives from government, public health, climate and environment bodies, academia and non-governmental organisations, highlight the urgent need for a cross-sectoral national heat risk commission. This can ensure planning takes all aspects of heat risk into account and goes beyond typical priorities for health, transport and buildings.

London’s Operation Helios, a multi-agency heatwave simulation exercise held in June 2024, brought together 80 participants across multiple sectors, including emergency services, local authorities and health agencies, to test their preparedness for a severe heat episode. This one-off coordinated event must be repeated regularly.

Read more: Five things the UK must do to prepare for the next heatwave

5. Take a low-carbon approach

Addressing heat risk must include reducing greenhouse gas emissions. Relying on energy-intensive solutions like mechanical air conditioning can worsen the problem by increasing emissions and contributing to local warming.

Taking early, proactive action opens up a wider range of low-emission measures, from raising awareness of simple behaviours to designing cooler, greener cities with low-carbon infrastructure. This includes more trees, shaded areas, cooling centres and water features such as fountains.

Resilience is possible. But it demands planning ahead, protecting the most vulnerable, and turning policy into action – before the next heatwave hits.

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Sara Mehryar receives funding from Z Zurich Foundation, Switzerland.

Anna Beswick receives funding from the Z Zurich Foundation, Switzerland.

Candice Howarth receives funding from the Economics and Social Research Council, British Academy, Natural Environment Research Council, EU Horizon 2020.