IPM Take
For decades, cardiovascular prevention focused on familiar risk factors: smoking, cholesterol, hypertension, obesity and diabetes. Climate change is adding a new one. Extreme heat and cold are increasingly linked to heart attacks, stroke, heart failure and cardiovascular mortality, particularly among older adults and vulnerable populations. The challenge is that many of the most effective interventions sit outside the healthcare system. Cooling centres, affordable energy, urban tree cover, climate-resilient housing and public warning systems may soon become as important to cardiovascular prevention as blood pressure control.
Executive Summary
A new American Heart Association scientific statement published in Circulation warns that extreme temperatures are becoming a growing threat to cardiovascular health. The statement highlights evidence linking both heat and cold exposure to heart attacks, stroke, heart failure and sudden cardiac death. While cold weather historically caused more cardiovascular deaths, researchers warn that rising global temperatures and more frequent heatwaves could shift this balance in coming decades. The authors call for coordinated action across research, healthcare and public policy, including improved heat preparedness, urban cooling strategies, climate-resilient infrastructure and better understanding of how cardiovascular medications interact with heat stress.
Why it matters
- Policymakers: Climate adaptation strategies may increasingly need to be integrated into cardiovascular prevention and public health planning.
- Health systems: More frequent heatwaves could place additional pressure on emergency departments, cardiovascular services and vulnerable patient populations.
- Clinicians: Evidence gaps remain regarding medication management, patient counselling and risk stratification during extreme heat events.
- Patients: Older adults, people with cardiovascular disease, outdoor workers and lower-income populations may face disproportionate risks from temperature extremes.
A heatwave is usually reported as a weather story. Increasingly, it may be a cardiovascular story.
A new scientific statement from the American Heart Association argues that extreme temperatures should be recognised as a growing threat to cardiovascular health, with implications extending far beyond hospitals and clinics.
The reason is simple.
The cardiovascular system is central to how the body regulates temperature.
During extreme heat, blood vessels widen and sweating increases to release excess heat. Blood pressure can fall, fluid levels decline and the heart must work harder to maintain circulation. For people living with cardiovascular disease, heart failure or multiple chronic conditions, this added stress can become dangerous.
The consequences can include heart attacks, stroke, arrhythmias, worsening heart failure and sudden cardiac death.
Historically, cold weather has been responsible for a greater number of temperature-related cardiovascular deaths because cold exposure remains more common globally.
That may be changing.
The statement notes that extreme heat events are becoming more frequent, more intense and longer-lasting. 2024 was officially the hottest year recorded since modern measurements began, and climate models suggest this trend will continue.
The impact is unlikely to be evenly distributed.
Older adults face some of the highest risks because ageing reduces the body’s ability to regulate temperature effectively. People living with cardiovascular disease, diabetes, kidney disease and multiple chronic conditions may be particularly vulnerable. Low-income communities often experience higher exposure because of limited access to cooling, poorer housing quality and reduced green space.
In many cities, neighbourhoods with the highest cardiovascular burden are often the same neighbourhoods experiencing the greatest heat exposure.
That is where this stops being solely a clinical issue.
The scientific statement explicitly calls for action beyond healthcare.
Recommendations include affordable access to cooling, public cooling centres, heat warning systems, urban greening programmes and climate-resilient infrastructure. Researchers also highlight the need to understand how common cardiovascular medications interact with heat stress, an area where evidence remains surprisingly limited.
The statement even points to the healthcare sector itself.
Healthcare contributes an estimated 8.5% of greenhouse gas emissions in the United States, prompting calls for more sustainable healthcare delivery models, including expanded telemedicine and lower-carbon healthcare infrastructure.
The broader lesson is increasingly difficult to ignore.
Climate change is no longer simply an environmental issue.
It is becoming a cardiovascular issue.
For IPM, this represents an important shift in how prevention is understood. The next generation of cardiovascular risk management may not only involve cholesterol, blood pressure and lifestyle interventions. It may also involve designing cities, health systems and public policies capable of protecting populations from increasingly hostile environmental conditions.
The future burden of cardiovascular disease may depend as much on climate resilience as clinical innovation.
