Extreme Climate Events and Heart Disease Risk: New Study Across 157 Chinese Cities Reveals Serious Health Impact

Climate change is no longer only an environmental issue. It is increasingly a public health challenge. A newly published research article examined how extreme climate events such as heatwaves, cold spells, and heavy rainfall affect cardiovascular disease risk across 157 Chinese cities between 2015 and 2020. The findings suggest that rising exposure to extreme weather may significantly increase heart disease risk, especially among older adults and other vulnerable groups.

This article summarizes the study about climate change and heart disease, heatwaves and cardiovascular disease, and extreme weather health risks.

What the Study Examined

Researchers analyzed data from more than 157 cities in China using two large national aging databases. They focused on adults aged 45 and older and studied whether extreme climate conditions were linked to cardiovascular disease, also known as CVD.

The three major climate exposures studied were:

• Extreme heat, defined as temperatures of 38°C or higher
• Extreme cold, defined as temperatures of -10°C or lower
• Extreme precipitation, defined as rainfall above 50 mm in a day

The study combined city-level spatial analysis with individual-level causal modeling to better understand both geographic trends and personal health risks.

Key Findings: Heat and Cold Increase Heart Disease Risk

The researchers found that both extreme heat and extreme cold were associated with higher cardiovascular disease rates.

Heatwaves Had the Strongest Effect

Each additional day of extreme heat was linked to:

• 1,128 more cardiovascular disease cases per 100,000 people at city level
• A 3.044% increase in individual cardiovascular disease risk

This suggests that prolonged exposure to very high temperatures may place substantial strain on the heart and blood vessels.

Cold Weather Also Increased Risk

Each additional day of extreme cold was linked to:

• 391 more cardiovascular disease cases per 100,000 people
• A 0.110% increase in individual cardiovascular disease risk

Cold weather can raise blood pressure, narrow blood vessels, and increase stress on the cardiovascular system.

Heavy Rainfall Was Also a Risk Factor

Extreme rainfall events were associated with a 1.620% increase in cardiovascular disease risk.

While rainfall did not show the same strong city-wide patterns as heat and cold, it still increased risk at the individual level.

Regional Differences Across China

The study found important geographic patterns:

• Heat-related heart disease effects were stronger in eastern China and weaker toward western regions
• Cold-related heart disease effects were stronger in western China and weaker toward eastern regions
• Northeastern cities showed especially high cardiovascular disease clustering

These differences may be influenced by infrastructure, humidity, healthcare access, urban design, and population age structure.

Who Is Most at Risk?

The researchers identified several high-risk groups more vulnerable to extreme climate events.

During Heat Events

Higher risk was found among:

• People approaching retirement age
• Smokers
• Residents in areas with high ozone pollution

Interestingly, higher BMI appeared to reduce some heat-related risk, though this does not mean obesity is protective overall.

During Cold Events

Higher risk was found among:

• People approaching retirement age
• Individuals with higher BMI
• Residents in high-ozone areas

During Heavy Rainfall

Higher risk was found among:

• Older adults
• Rural residents
• People nearing retirement age
• Individuals without spouses

These findings show that climate-related health threats do not affect everyone equally.

Why Extreme Weather Affects the Heart

Extreme climate events can trigger several physical responses that increase heart disease risk:

• Dehydration during heatwaves
• Increased blood thickness and stress during cold weather
• Sudden blood pressure changes
• Inflammation
• Reduced air quality
• Physical strain from flooding or disrupted healthcare access
• Emotional stress during weather emergencies

For people with existing heart conditions, these risks may be even higher.

What This Means for Public Health

The study recommends stronger climate-health planning, including:

• Linking weather alerts with healthcare systems
• Warning vulnerable residents before heatwaves or cold spells
• Expanding cooling centers and warming shelters
• Improving green spaces in cities
• Reducing ozone and air pollution
• Prioritizing prevention funding in high-risk regions
• Delivering health education to older adults

As climate extremes become more common, healthcare systems may need to adapt quickly.

Practical Heart Health Tips During Extreme Weather

If you are concerned about heatwaves, cold snaps, or storms, consider these steps:

During Hot Weather

• Stay hydrated
• Avoid outdoor exertion in peak afternoon heat
• Use fans or air conditioning
• Monitor blood pressure if advised by your doctor

During Cold Weather

• Dress in layers
• Warm indoor spaces safely
• Avoid sudden strenuous activity outdoors
• Take medications consistently

During Heavy Rainfall or Storms

• Keep medication supplies ready
• Avoid floodwater exposure
• Have an emergency contact plan
• Seek help quickly if chest pain or symptoms occur

Final Takeaway

This major China-based study adds to growing evidence that extreme climate events can significantly raise cardiovascular disease risk. Heatwaves had the strongest effect, but cold spells and heavy rainfall also increased danger, especially for older adults and vulnerable populations.

As global temperatures rise and weather patterns become more unstable, protecting heart health during extreme weather may become an essential part of preventive medicine.

Source

Wei L, Liang Y, Wang X, Zhang W, Zhang L, Fang Y. Assessing the Impact of Extreme Climate Events on Cardiovascular Disease in 157 Chinese Cities (2015–2020): A Spatial and Causal Analysis. Research Article, published April 21, 2026.

Disclaimer

This blog is for educational and informational purposes only. It does not provide medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional regarding personal health concerns or cardiovascular symptoms.