A new study has found that heart-related deaths due to extreme heat are expected to rise between 2036 to 2065 in the United States. The study, funded by the National Institutes of Health, suggested that climate change, which is causing an increase in extreme heat, is putting people with cardiovascular disease at high risk.

The researchers, whose work is published in Circulation, predict that adults aged 65 and older and Black adults will likely be disproportionately affected.

How Extreme Heat Affects the Heart

While currently, less than 1% of cardiovascular-related deaths can be attributed to extreme heat, a modelling analysis suggests that this situation could change due to an anticipated increase in the number of summer days with temperatures exceeding 32 degrees Celsius, accounting for humidity and creating what is known as the heat index.

This extreme heat will have a more significant impact on older and Black adults, who often grapple with preexisting health conditions and economic challenges that affect their access to healthcare and living conditions. This includes the absence of air conditioning or residences in areas that can trap heat, commonly referred to as “heat islands.”

Dr Sameed A. Khatana, a cardiologist and assistant professor of medicine at the University of Pennsylvania in Philadelphia and one of the study authors, emphasised that the unequal effects of extreme heat on various populations raise concerns about health equity and the potential to exacerbate existing health disparities.

How the Heart Responds to Heat

To generate these predictions, the researchers analysed data in 48 states between May and September from 2008 to 2019, where over 12 million cardiovascular-related deaths occurred.

The research also found that the heat index exceeded 32 degrees Celsius on approximately 54 occasions each summer, resulting in an estimated 1,651 annual cardiovascular deaths nationally.

While most people can adapt to extreme heat through mechanisms like sweating to cool the body, individuals with underlying health issues, such as diabetes and heart disease, may face different responses and elevated risks of heart attacks, irregular heart rhythms, or strokes.

How to Prevent Heat-Related Heart Problems

Lawrence J. Fine, M.D., a senior advisor at the National Heart, Lung, and Blood Institute (NHLBI), emphasised the importance of people with underlying health risks taking additional precautions to avoid extreme temperatures, in a statement.

The authors also highlighted certain cooling methods implemented by some cities, such as tree planting for shade, the establishment of cooling centres equipped with air conditioning, and the use of heat-reflective materials for streets and roofs.

They also recommended that people stay hydrated, avoid strenuous activities during peak heat hours, wear light clothing, and seek medical attention if they experience symptoms such as chest pain, shortness of breath, dizziness, or nausea.

Implications for Public Health Policy

The study’s findings have implications for public health policy and planning, especially as climate change is expected to worsen in the coming decades. The researchers urged the government and the industry to work together to ensure the safety and benefits of AI.

They also called for more research on the effects of extreme heat on cardiovascular health and mortality, as well as on the potential interventions to reduce them.

The study was conducted by researchers from several institutions, including Harvard University, Columbia University, Boston University, Yale University, Stanford University, and Johns Hopkins University.