LAS VEGAS — In the scorching deserts of the Southwest, two neighboring counties are grappling with the deadly toll of extreme heat, but their responses tell starkly different stories. Maricopa County, Arizona, home to Phoenix, has seen a promising decline in heat-related deaths despite record-breaking temperatures, thanks to proactive measures like 24/7 cooling centers. In contrast, Clark County, Nevada, which includes Las Vegas, recorded a staggering 513 heat fatalities in 2024, more than tripling from just three years prior, highlighting the urgent need for better preparedness as climate change intensifies heat waves.
Dr. Jeffrey Johnston, the chief medical examiner for Maricopa County, has witnessed the escalating crisis firsthand. Heat-related deaths in the county surged from several dozen in 2014 to 645 in 2023. “The surges were so intense and long, so we really did approach it like a mass casualty event,” Johnston said of recent summers. But after years of investment in heat mitigation, the county reported a dip last year, with 602 confirmed heat deaths in 2024, down from the previous year's total. Preliminary data for this year shows even fewer, with 185 confirmed so far compared to 284 at the same point last year.
Maricopa County's efforts include expanding cooling centers, hiring a full-time heat relief coordinator in 2024, and ramping up public messaging in English and Spanish. These initiatives appear to be paying off, even as Phoenix endured its hottest summer on record in 2024, with 113 consecutive days at or above 100 degrees and 31 straight days at or above 110 degrees the year before. “We were able to reverse the trend,” said Dr. Nick Staab, chief medical officer for the county’s health department. “We’ve been plugging away at this for many years now, and we’re going to keep plugging away because every one of these deaths is preventable.”
In Clark County, the situation has been more dire. Heat deaths jumped dramatically, reaching a record 513 in 2024, according to preliminary figures that officials say will likely remain in the hundreds this year. Ariel Choinard, a scientist at the Desert Research Institute in Las Vegas, described last summer's temperatures hitting 120 degrees as a turning point. “There was something about seeing 120 degrees in Las Vegas that made people be like, ‘Oh, my gosh, wait, this is really serious,’” she said. Choinard, who leads the Nevada Heat Lab, has been studying Maricopa's strategies and acknowledges the gap. “They started the work around heat earlier than we have in this region, so in many ways they’re ahead of us,” she added.
Heat remains the deadliest weather-related killer in the U.S., outpacing hurricanes, floods, and tornadoes, according to the National Weather Service. As climate change drives more frequent and intense heat waves, these counties in one of the nation's fastest-warming regions illustrate the costs of delay. Vulnerable groups bear the brunt: the homeless, low-income residents, outdoor workers, the elderly, and those with medical conditions. In Maricopa County last year, homeless individuals accounted for 49% of heat-related deaths, and 57% involved substance use. A Southern Nevada Health District report found at least 34% of Clark County's 2024 heat deaths were among the homeless, with links to drugs and alcohol, and higher rates in low-income ZIP codes.
Maricopa officials responded to the 2023 spike by surveying cooling center users, discovering most were homeless or unstably housed, yet centers closed evenings and weekends. In 2024, Phoenix launched 10 round-the-clock cooling centers, which reopened this summer. The county's meticulous tracking of deaths—investigating any case when temperatures reach 95 degrees or higher—has created the nation's most comprehensive records. “We’d rather evaluate more cases that ultimately don’t turn out to be heat-related than risk missing some,” Johnston said. Over 300 deaths remain under investigation.
Clark County's response has lagged, with officials calling recent summers “slow-moving disasters.” Jeff Quinn, public health preparedness manager at the Southern Nevada Health District, noted the strain on hospitals. “We have limited capacity with our hospitals and health care system, and you see when there’s an increase in temperature, the emergency departments surge,” he said. “That impacts the ability of hospitals to respond to the next incident.” The county's cooling centers aren't 24/7 due to resource constraints, a mismatch for Las Vegas's nonstop lifestyle. “This is a 24/7 town,” Quinn said. “If you want to go grocery shopping at 2 a.m., there’s a grocery store open, and it’s air conditioned.”
A Nevada Heat Lab survey revealed awareness gaps: “Over 47% of the people who responded to our survey were not aware about cooling stations in southern Nevada,” said David Almanza, who oversaw the survey. “And these were people that were in cooling stations when we were surveying them.” To address this, Clark County introduced free bus passes and ride-sharing to centers this summer, stocked Narcan for overdoses, and began earlier public outreach, mirroring Maricopa's approach. “The fact that Maricopa County managed to bring down deaths in the midst of an exceptionally hot and truly brutal summer in 2024 is really remarkable,” Choinard said. “It’s not a one-size-fits-all solution, but my hope is that we will figure out something that works for us here.”
This summer was milder in Las Vegas compared to 2024's streak of days above 110 degrees, potentially lowering the death toll, but officials warn against complacency. Funding remains a critical hurdle for both counties. Maricopa has relied on 2021 American Rescue Plan Act funds, set to expire after next year's heat season. In Clark, programs like transportation aid came from a federal grant and United Way partnership, but Quinn said the budget exhausted quickly. “That budget is fully exhausted in the first month of summer,” he noted.
Broader political shifts add uncertainty. Quinn expressed concerns about federal funding cuts under the Trump administration, particularly for climate-related grants. “We’re seeing this backlash on climate change, like with diversity, equity and inclusion, where people want to eliminate funding any grant that mentions climate change,” he said. In response, White House spokesman Kush Desai stated, “local officials concerned about heat mitigation should focus on unleashing economic forms of American energy to reduce electricity costs for everyday Americans.”
Despite these challenges, experts emphasize that heat deaths are preventable with targeted interventions. Maricopa's success in bucking the upward trend offers a model, but Clark officials are adapting it to local needs, such as partnering with resorts for extended cooling access. As temperatures continue to rise, the experiences of these counties underscore the need for sustained investment and innovation to protect the most vulnerable.
Looking ahead, both counties plan to evaluate this year's data fully. Maricopa aims to maintain its downward trajectory, while Clark seeks to build on nascent efforts. “This threat isn’t going to go away. It will impact us regardless of who’s working on it or whether there’s funding or not,” Quinn said. “We just have to do our best with what limited resources we have.” With climate projections forecasting even hotter summers, the scramble to save lives in the Southwest serves as a national warning about the human cost of inaction.
The divergence between Maricopa and Clark highlights how early action can mitigate disaster. As Choinard put it, the progress in Phoenix is inspiring, but Las Vegas must catch up quickly. In a region where heat waves are becoming the norm, the path forward depends on bridging resource gaps and prioritizing public health amid environmental shifts.