Brutal heat continues to plague the south-west US, with excessive heat alerts lingering long into September as parts of the region set grim new records for deaths connected to the sweltering temperatures.
Autumn has offered little reprieve for cities that have already spent months mired in triple-digit temperatures. This week, Las Vegas, Nevada; Phoenix, Arizona; and Palm Springs, California, are all grappling with severe weather, with highs that have pushed over 100F (38C). More than 16 million people in the US were under heat alerts on Friday, according to the National Weather Service, mostly clustered in the southern tips of Nevada, Arizona and California.
“Late-season heat is dangerous because people are fatigued from fighting heat all summer,” the NWS forecast office in Las Vegas cautioned in an alert, which warned of extreme weather expected to last through the weekend and into next week. “This is especially true this year,” it added, “as 2024 continues to break all-time heat records.”
Fueled by the climate crisis, and often exacerbated by concrete cityscapes that cook when temperatures rise, heatwaves are getting longer, larger and more intense.
Las Vegas had its 102nd day of temperatures above 100F on Friday, a new record for the most days in a single year. Several states, including Arizona and California, have experienced their warmest summers on record this year, according to the National Oceanic and Atmospheric Administration, and forecasters are predicting that 2024 may rank as the hottest year – a record just set in 2023.
“But it’s not over,” NWS Las Vegas said on Twitter, noting the heat warnings lingering in the forecast through the weekend.
The scorching and sustained heat has taken a devastating toll; heat already ranks as the most lethal weather-related disaster in the US, and deaths are increasing. Heat-associated fatalities are growing across the south-west, where shadeless streets can grow hot enough to cause second-degree burns in seconds. As dangerously hot weather stretches past summer and into spring and fall, the risks for those who don’t have access to cooling have continued to rise.
In Arizona’s Maricopa county, home to Phoenix, 664 fatalities are believed to have been linked to the heat this year , according to public health officials, who are still working to confirm more than half of them. Southern Nevada, where Las Vegas is located, has seen more deaths this year than in any year prior, with officials confirming this week that there have been 342 fatalities linked to the heat. This surpassed last year’s record, which marked an 80% increase over 2022.
But even these tragically high numbers are believed to paint only part of the picture. Heat deaths can be difficult to track, especially among high-risk populations including in unhoused communities. “We will inevitably see this number climb,” Melanie Rouse, Clark county’s coroner, told the Las Vegas Review-Journal.
Older people, children and people with underlying health conditions are among the most at risk, especially among those without access to air conditioning, but first responders have also reported that heat-related emergencies have been climbing for workers.
“Delivery drivers, warehouse operators, our construction trades – basically anyone who has to work outside – we have seen emergencies from them and people with regular medical emergencies, and during a normal day the heat causes them to succumb,” Scott Vivier, the deputy fire chief in Henderson, a city south-east of Las Vegas, said in July.
Vivier’s department is among the first in the region to use a new tool called the polar pod, which enables emergency responders to pack someone in ice and water while they transport them to the hospital. Vivier said it’s had an incredible impact on their ability to save lives, and that they’ve even been trained to use the pods to revive overheated pets.
Exposure to prolonged extreme heat can also have lingering effects that are harder to quantify. As residents across the south-west yearn for the coming of a cooler autumn, public health clinicians have cautioned the heat can pack a psychological punch as well, leading to symptoms like irritability, anxiety and difficulty concentrating.
