Las Vegas is tallying more heat-related deaths. It’s still an undercount

The party capital of the United States is rapidly becoming a hot spot for heat-related deaths — something officials are beginning to better tally. It’s not an exact science.

“We may still miss heat as a factor during some of these months,” said Clark County Coroner Melanie Rouse, whose office studies deaths in Southern Nevada. “But we’re doing a better job of trying to capture that.”

That’s why, after a summer heat that has far surpassed any in recorded history, the growing number of people who have died is so staggering. So far this year, 402 deaths were identified as heat related — a 30 percent increase from 309 deaths in 2023.

There’s no way to tell when the Clark County coroner’s office will finalize the total death count as medical examiners race to close cases, most of which take 90 days to examine comprehensively.

On heat intensity, Southern Nevada is still second to Maricopa County in Arizona, which reports the data weekly and has seen 466 heat-related deaths in 2024. Rouse, who came to Las Vegas from Phoenix in 2021, brought with her intimate knowledge of how the country’s hottest city has risen to the occasion to track such deaths.

“I thought it was important for us to follow suit so we have a good way to extract the data and really know what’s happening in our communities,” she said.

When is heat considered in a death investigation?

Much of the answer to the question of when heat is considered a factor in someone’s death is determined by observation and circumstance.

“When we look and there’s not a more compelling cause of death that excludes heat as a factor, we will include heat as part of that condition if other criterion are met,” Rouse said.

A wide variety of health characteristics may lead examiners to believe a lack of tolerance of heat could have been at play, such as young or old age, obesity, or pre-existing conditions such as heart disease or endocrine disorders. Someone new to the desert heat whose body wasn’t properly adjusting is something the coroner’s office sees often, too.

Physical indicators such as hydration levels, evidence that someone tried to take their clothes off or signs of vomiting may put heat in play, as well. Toxicology reports conducted later can reveal whether a patient was taking drugs — prescription or recreational — that might have decreased the body’s ability to regulate heat.

While there isn’t necessarily a temperature threshold for when heat is considered, Rouse said looking at a base “heat death line” that considers relative humidity and temperature is helpful.

Researcher Elizabeth Schickele, who studied heat deaths in World War II, pioneered the concept. She found that almost every death in her research fell above the line that she believed would mark when temperature and humidity values lead to heat-related death.

The indicator means that Las Vegas should generally consider heat a factor in most deaths when temperatures are above 95 degrees, when considering the city’s average humidity, Rouse said. In total, 133 days in 2024 met the coroner’s standard with a maximum temperature above 95 degrees.

There were 112 days this year with temperatures above 100 degrees, according to the National Weather Service. Previously, that record was held in 1947, when there were 100 triple-digit heat days.

Las Vegas broke its all-time record for a single temperature reading with 120 degrees on July 7. Weather service meteorologists like Dan Berc hope relief is brought next summer with a more active rainy season. This year’s was particularly dry.

“The hope is that this year is anomalous, but we’ll see,” said Berc, who coordinates heat advisories in Southern Nevada.

Heat-related deaths are undercounted across the country

Despite the overhaul of Clark County’s approach to counting heat-related deaths, experts agree that medical examiners across the country and world are still falling short of a truly accurate toll.

Kristie Ebi, a global health professor at the University of Washington, has seen metro areas get better at doing so in her years studying the intersection of public health and heat.

There’s no federal standard or law dictating how cities should keep track of heat-related deaths.

A country-wide study published in August found that 2,325 people died from the heat in 2023, the most ever recorded in the data set that began in 1999. The authors acknowledged that the process of including heat in death certificates is not the same in every state and that examiners are considering heat more with every passing, hotter year.

“The numbers are always higher than what’s reported,” Ebi said. “And that, in essence, is a challenge I don’t think can ever be solved.”

That’s because the priority of narrowing down whether heat played a factor in deaths that can be attributed to other causes should never supersede saving a life or working on preventing the deaths in the first place, she said.

“All heat-related deaths are preventable, so how much effort do you want to put into getting an accurate number, and how much effort do you want to put into having much better early warning and response systems?” Ebi said.

Contact Alan Halaly at ahalaly@reviewjournal.com. Follow @AlanHalaly on X. Staff writer Katie Futterman contributed to this report.