Study Links Extreme Weather Events to Modest Increases in Cardiovascular Disease Burden in Chinese Cities

A study published in the American Journal of Preventive Medicine has found that extreme weather conditions, including heatwaves, cold snaps, and heavy rain, are associated with increased risks of heart disease. The research examined data from 157 Chinese cities between 2015 and 2020, focusing on extreme heat, extreme cold, and heavy precipitation in relation to cardiovascular disease burden.

@ABC reported these findings, highlighting how such environmental factors contribute to global health challenges.

4 degrees Fahrenheit, the individual risk of heart disease increased by about 3%. Days with temperatures equal to or less than 14 degrees Fahrenheit saw a smaller rise, with the risk increasing by less than 1%. Additionally, any day with more than about two inches of rain was linked to an almost 2% increase in heart disease risk.

'Broadly, we found that extreme heat and extreme cold were associated with a higher city-level cardiovascular disease burden across 157 Chinese cities from 2015 to 2020,' said Linjiang Wei, a PhD-level researcher at Xiamen University and one of the study's primary authors.

Wei emphasized that these associations do not imply a single extreme weather day will cause a cardiovascular event in any individual. 'This does not mean that a single hot or cold day will necessarily cause a cardiovascular event in any one person.

Rather, it suggests that repeated exposure to extreme weather can shift cardiovascular risk upward at the population level in meaningful ways,' he stated. Environmental factors account for at least one in five of the 20 million annual deaths from cardiovascular disease worldwide, according to Dr. Jennifer Miao, a cardiologist at Yale School of Medicine and an ABC News Medical Unit fellow.

She noted the broader implications for health, including lung disease and cancers. Certain groups face greater risks from weather-related cardiovascular issues, the study revealed.

People younger than retirement age, smokers, those with high body mass index (BMI), or residents in high-ozone or rural areas were all more vulnerable. Regional differences also emerged: heat had a stronger impact on heart disease risk in eastern areas of China, while cold exerted a greater effect in western areas. The findings gain urgency amid rising extreme weather linked to climate change.

An estimated 84% of heat wave days between 2020 and 2024 would not have happened without global warming, as detailed in a 2025 Lancet report on health and climate change. Wei advised precautions like staying hydrated, avoiding outdoor exertion during extreme conditions, maintaining stable indoor temperatures, and keeping medications accessible.

The study was authored by researchers including Linjiang Wei, with contributions noted from experts like Dr.

Jennifer Miao. Megan Still, a neurosurgery resident at the University of Florida and a member of the ABC News Medical Unit, wrote the article on the study, published on April 21, 2026, at 12:37 AM. @ABC reported on these details, underscoring the need for ongoing research into how cumulative weather exposures interact with factors like medications and underlying health conditions.