Increasing Frequency and Impact of Deadly Heat Waves in the US

Heat waves, such as the recent one that swept across parts of the South and Midwest, claiming the lives of more than a dozen individuals, are becoming more prevalent. Experts warn that these extreme weather events, which cause more fatalities than hurricanes and tornados, are likely to escalate in the future.

A heat dome, which exerted pressure on the Texas power grid resulting in 13 fatalities, expanded eastward and is anticipated to center over the mid-South during the upcoming weekend. Forecasters predict heat index levels reaching up to 112 degrees Fahrenheit (44 degrees Celsius) in certain areas of Florida in the coming days.

Among the heat-related deaths in Texas, eleven occurred in Webb County, encompassing Laredo. The deceased individuals, ranging in age from 60 to 80 years old, often had pre-existing health conditions, as confirmed by the county’s medical examiner. Additionally, two fatalities were reported in Florida, where hikers succumbed to extreme heat at Big Bend National Park.

Scientists and medical experts emphasize that without increased efforts to combat climate change, which has caused rising temperatures, the number of deaths attributed to extreme heat will surge each summer in the United States. Particularly vulnerable are regions unaccustomed to warm weather, necessitating the adoption of strategies to prepare for heatwaves, similar to the preparedness for snowstorms in Boston, as noted by Dr. Gaurab Basu from the Center for Climate, Health, and the Global Environment at Harvard T.H. Chan School of Public Health. Suggestions include planting more trees to enhance urban shade and investing in green technologies like heat pumps for home cooling and heating.

Currently, extreme heat is the deadliest weather phenomenon in the United States, surpassing the toll of hurricanes, tornadoes, wildfires, and flooding. The prolonged duration and wide geographic impact of heatwaves contribute to their lethal nature, often catching people off guard.

Phoenix, known as the hottest major city in America, faces an excessive heat warning, with dangerously high temperatures forecasted for south-central Arizona during the upcoming weekend. The range of 107 to 115 degrees Fahrenheit (41.6 to 46.1 degrees Celsius) poses significant risks, prompting concerns about the continuing loss of lives.

Counting heat-related deaths has become a scientific process in Maricopa County, Arizona, which encompasses metro Phoenix. The county not only records deaths resulting from direct exposure but also considers heat as a significant contributing factor in cases of heart attacks and strokes.

Dr. Sameed Khatana, a cardiologist, emphasizes the importance of including deaths where heat plays a substantial role in fatalities, such as those caused by heart failure. His research from the previous year estimates that between 13,000 and 20,000 adult deaths from 2008 to 2017 were linked to extreme heat, with approximately half attributed to heart disease. Older individuals and those with underlying health conditions like diabetes, obesity, and heart disease face the highest risk.

While hurricanes, flooding, and wildfires capture attention due to their dramatic nature, heatwaves pose a greater challenge, as they affect vast areas for extended periods. Those who are socially isolated or living on the fringes of society are particularly susceptible.

To address the impact of extreme heat, the city of Phoenix has implemented various measures, including shelters for the homeless, cooling centers in libraries and community spaces, and the distribution of essential supplies like bottled water, hats, and sunscreen. They have also established a program called “Cool Callers” in which volunteers check on vulnerable residents during hot periods.

Even the Phoenix Zoo has taken precautions to cool down its animals, employing techniques such as water sprays, frozen treats, shaded areas, and cooled water pools.

The issue of extreme heat deaths extends beyond the United States, with Mexico also grappling with its consequences. Mexican health authorities recently acknowledged the deadliness of a heatwave that claimed at least 112 lives this year, despite previous dismissals by President Andrés Manuel López Obrador. In the past two weeks alone, there has been a significant surge in heat-related fatalities, nearly tripling the numbers from 2022.

Furthermore, international scientists conducting a rapid study revealed that human-caused climate change made record-breaking April temperatures in Spain, Portugal, and northern Africa approximately 100 times more likely. Similarly, a searing heatwave in southern Asia in April, with temperatures reaching up to 113 degrees Fahrenheit (45 degrees Celsius), was made at least 30 times more likely due to climate change, resulting in widespread hospitalizations and deaths.

This article was contributed by Adrian Sainz in Memphis, Tennessee; Michael Goldberg in Jackson, Mississippi; Jim Salter in St. Louis, Missouri; Curt Anderson in Miami, Florida; and Sara Cline in Baton Rouge, Louisiana.

Frequently Asked Questions (FAQs) about heat waves

More about heat waves

• Rising Frequency of Heat Waves
• Impact of Climate Change on Heat Waves
• Heat Wave Preparedness Guidelines
• Heat-Related Deaths and Vulnerable Populations
• Comparison of Mortality Risks from Different Weather Events
• Global Impacts of Heat Waves