3 Climate Conditions That Are Dangerous for Your Heart

Changing weather conditions may impact heart health in surprising — and potentially tragic — ways, according to a recent study.

Weather events that feature soaring heat, plunging cold or high levels of certain air pollution can significantly raise the risk of death from heart attack, according to a large study published in the American Heart Association’s journal Circulation.

The danger is especially high for women and older adults, and is greatest when there is a combination of extreme heat and high levels of a type of air pollution known as fine particulate matter.

For the study, researchers in China pored over data from 202,000 heart attack deaths in one Chinese province between 2015 and 2020 and discovered the link between these types of extreme weather and the risk of fatal heart attacks. Read on for the details of their findings.

1. Heat waves

When it came to hot weather, the researchers found that the risk of fatal heart attack was:

• 18% higher during ­two-day heat waves with heat indexes at or above the 90^th percentile (ranging from 82.6 to 97.9 degrees Fahrenheit).
• 74% higher during four-day heat waves with heat indexes at or above the 97.5^th percentile (ranging from 94.8 to 109.4 degrees Fahrenheit).

2. Cold snaps

When it came to cold weather, the researchers found that the risk of a deadly heart attack was:

• 4% higher during two-day cold snaps with temperatures at or below the 10^th percentile (ranging from 33.3 to 40.5 degrees Fahrenheit).
• 12% higher during three-day cold snaps with temperatures at or below the 2.5^th percentile (ranging from 27 to 37.2 degrees Fahrenheit).

3. Air pollution

The risk of a fatal heart attack was two times as high during four-day heat waves that had fine particulate pollution above 37.5 micrograms per cubic meter, the study found.

However, researchers did not see an equivalent rise in heart attack deaths on days when cold snaps combined with high levels of fine particulate pollution.

How to protect yourself

In a summary of the study findings, senior author Dr. Yuewei Liu — an associate professor of epidemiology in the School of Public Health at Sun Yat-sen University in Guangzhou, China — notes that extreme temperature events have become “more frequent, longer and more intense.”

Liu adds that the presence of fine particulate matter in the air is also a worldwide issue.

While Liu notes that it is not clear if and how exposure to extreme temperatures and fine particulate pollution might increase the risk of fatal heart attacks, the study author still suggests that people take precautions when these conditions are present:

“Our findings provide evidence that reducing exposure to both extreme temperatures and fine particulate pollution may be useful to prevent premature deaths from heart attack, especially for women and older adults.”

Liu urges people to follow weather forecasts and adjust their behavior accordingly. Steps Liu recommends taking to protect yourself during these conditions include:

• Remain indoors when temperatures are extreme.
• Use fans and air conditioners during hot weather.
• Wear clothes that are appropriate for prevailing weather conditions.
• Remain hydrated.
• Use window blinds to reduce indoor air temperatures.

On days when fine particulate pollution levels are high, Liu says you should:

• Use air purifiers inside and wear masks outside.
• Avoid busy highways when walking.
• Refrain from strenuous outdoor activities.