The world’s rising temperature brings major health risks, not all of them obvious. The possibility of dehydration and heatstroke is well known, but before that point, the human heart is already under extra strain.
A new study published in Circulation revealed that heat has contributed to thousands of heart disease deaths in recent decades — and the number per year during 2036-65 is projected to more than triple the numbers from 2008-19, Stat News reported.
The human body’s response to heat relies on blood flow. Sweat cools off blood close to the skin; the heart circulates the hot blood outward from the core and the cooled near-surface blood inward to protect the organs from overheating. These responses are part of heat stress.
All of that extra blood flow means the heart pumps faster and harder when it gets hot — which is especially bad news for someone with existing cardiovascular problems. Heat can trigger a heart attack, stroke, or heart failure more easily in those who are susceptible.
Why does heat stress matter?
This new study said that heat accounted for 1,651 heart disease deaths in the United States on average each year from 2008 through 2019 — findings consistent with other studies linking heat and cardiovascular deaths. It then predicted how those numbers might look by the mid-century as the Earth’s temperature continues to rise thanks to heat-trapping air pollution.
The study looked at a more conservative scenario — in which pollution increases only a little — and a more severe possibility. With less pollution, it predicted annual excess heat deaths would rise by 162% to 4,320 between 2036 and 2065. With more pollution, the number was 5,491 deaths, a 233% increase.
According to Stat News, some populations are more vulnerable than others. The elderly are at more risk than the young, and Black adults are likely to see four times the increase in their death toll compared to white adults. Outside the U.S., hotter regions of the world and those with less access to air conditioning are likely to be more affected, leading to a high death toll.
Robert Brook, the executive director of cardiovascular prevention at Wayne State University School of Medicine, told Stat News, “This is a bad harbinger for the rest of the world that is less climate-resistant generally than we are.”
What can we do about heart disease deaths from heat?
Sameed Khatana, senior author of the study, told Stat News that preventing the future predicted in the study would require recognizing heat as a public health issue. Khatana proposed that hospitals could become cooling centers and that healthcare providers could keep an eye out for patients struggling in the heat.
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