US Heat Deaths Reached a Record High Last Year

Summers in America have been getting deadlier every year since 2016, with a record 2,325 heat deaths last year, according to a new study. Even that number, researchers say, is probably an undercount because excess heat kills in many ways and different counties record deaths in different ways.

• "The way that death certificates are filled out, the people that are filling them out don't always know the full circumstances that led to the death. So we're only probably scratching the surface of it," study co-author Jeffrey Howard, associate professor of public health at the University of Texas at San Antonio, tells CNN. "The fact that you see this trend tells me that there's probably many more deaths that we just are unable to measure."

• Howard and other researchers looked at death certificate data from 1999 to 2023, USA Today reports. They found that between 1999 and 2016, the number of heat-related deaths went up and down from year to year, with the overall trend a decline of 1.4% per year. But a sharp upswing began in 2016, with heat-related deaths jumping an average of 16.8% from that year to 2023.
• The study, published in American Medical Association journal JAMA, found that heat deaths were concentrated in Arizona, California, Nevada, and Texas. "These are all hot areas, so you may expect that, but so much more could be done to plan for these hot days," Howard says.

• "As temperatures continue to rise because of climate change, the recent increasing trend is likely to continue," researchers wrote. "Local authorities in high-risk areas should consider investing in the expansion of access to hydration centers and public cooling centers or other buildings with air conditioning."
• The study did not include figures for this year, in which many local and global heat records have been broken. "On the whole, it seems that things are getting worse and not better," Howard tells USA Today.

(More excessive heat stories.)