Why Your Risk of Having a Fatal Heart Attack

New research suggests extreme temperatures can significantly increase your risk of a fatal heart attack. However, health experts say there are simple steps you can take to reduce your risks. High levels of air pollution, such as smoke from wildfires, can also increase your likelihood of having a fatal heart attack. According to the National Oceanic and Atmospheric Administration (NOAA), the Earth’s average global temperature was 1.89 degrees F (1.05 degrees C) above average in June, making it the hottest on record. Wildfires in Canada also contributed to unsafe pollution levels in many areas throughout the US earlier this year. While this combination has put a damper on outdoor summer plans for many people, it can also significantly increase health risks. Specifically, new research suggests that extremely hot or cold temperatures may increase the risk of fatal heart attack. Pollution levels can, too. For the studyTrusted Source, published on July 24, researchers looked at more than 202,000 heart attack deaths in the Chinese province of Jiangsu between 2015 and 2020. They noted a “significantly associated” risk that a person would die from a heart attack if temperatures were extremely hot or cold or there were high levels of particulate matter pollution (PM). According to The Centers for Disease Control and Prevention (CDC)Trusted Source, PM refers to particles of solids or liquids in the air, such as smoke, dust, or dirt. The news may not be welcome to people, as the summer of 2023 has seen a return to pre-pandemic travel and big-ticket events like concerns after three years of wrestling with the health and economic fallouts stemming from COVID-19. But doctors say the new research is critical. Ever feel like you’re moving a little slower and breathing heavier in the heat, even if you’re just taking a leisurely stroll from a lounge chair to the diving board? You’re not imagining it. “Routine tasks, such as lifting, carrying moderately heavy items such as shopping bags, and walking up an incline, are significantly more taxing in extreme heat and can reach the tipping point for a cardiovascular event where they would not have reached that threshold in more moderate temperatures,” says Prabhu. Extreme heat triggers physiological responses to help the body adapt and survive — notably, sweat and dilation of blood vessels close to the skin’s surface. “This causes the heart to work harder and faster to maintain adequate blood flow to vital organs,” says Tadwalkar. “This increased workload places additional stress on the heart.” Prabhu says this risk increases when people perform high cardiovascular output activities, such as long-distance running or a long hike. What goes out needs to go back in — in other words, it’s important to replenish fluids in high heat. In hotter temperatures, people can become easily dehydrated, which can increase heart attack risk, Prabhu says. “Dehydration and reduced blood flow to the heart can also indirectly make blood more prone to clotting, potentially leading to blockages in coronary arteries, thus triggering a heart attack,” he says. While air pollution risks often center around the lungs and respiratory health, healthcare providers say it can also affect the heart, largely because the body’s vital organs work together. What affects one can affect another. “PM2.5 particles are tiny particles that float in the air, risking inhalation deep into the lungs or entrance into the bloodstream,” explains Tadwalkar. “Once in the body, these particles can cause inflammation and oxidative stress, leading to damage to blood vessels and the heart.” “High pollution days may be classified as those where PM2.5 levels, often measured in micrograms per cubic meter, exceed specific guidelines set by health organizations,” Tadwalkar says. Tadwalker says that specific populations are at a higher risk for a fatal heart attack during extreme heat or cold or when there are high levels of air pollution. These populations include: People with pre-existing cardiovascular conditions, like coronary artery disease and hypertension Pregnant people People with diabetes Aging individuals However, Prabhu advises everyone to take precautions during extreme weather or if there is a high amount of air pollution. “We will often see young and healthy people who are doing something out of the ordinary for them, such as a marathon or long hike [and] have not adequately prepared as well,” Prabhu says. “The key is to know your limits and have a low threshold to stop when doing an activity that you don’t do on a regular basis. ‘Start low and go slow’ is a good mantra for activity during extremes of weather.” Stay hydrated. “During extreme heat, it is crucial to stay hydrated by drinking plenty of water,” Tadwalker says. Find a chill spot. “Seek shade or air-conditioned environments, when possible, to avoid overheating,” Tadwalker says. Modify your workout. If you plan to work out outdoors, prepare to scale back as needed. “For example, if you typically run 3 miles at a 7-minute mile, maybe try 2 miles at 9-minute miles or walking,” Prabhu says. “It’s OK to curtail your speed and distance in times of extreme weather.” Listen to your body. If you set out on a 5-mile run and aren’t feeling it, take stock and consider pivoting. “Listen to your body and rest in a cool place if you experience warning signs like dizziness or weakness, and seek medical help if symptoms persist or worse,” Dasgupta says. Dress cool. Tadwalker says that loose, lightweight clothing allows for better air circulation. Avoid peak heat. Dasgupta says it’s usually hottest between 10 a.m. and 4 p.m., and the risk of overexertion and stress on the heart is highest during this period.