Federal Heat Death Counts May Miss Thousands in Fresno and the Valley — and That Affects How Officials Respond

The federal agency counting how many Americans die from heat has been undercounting them for years — including right here in Fresno County, where the real toll may be more than six times what official records show.

That gap matters because how many deaths officials believe are happening shapes whether they declare emergencies, where they put cooling centers, and how seriously they warn the public about coming heat waves.

Since 2018, the Centers for Disease Control and Prevention has reported an average of about 1,700 heat-related deaths nationally each year. But a recent investigation by NPR and Boston University projects the real number is closer to 9,000 — and locally, researchers estimate Fresno County averages 27.6 heat deaths a year, while CDC data shows only 4.2.

In Kern County, the gap is nearly as wide: researchers estimate 23.3 annual heat deaths, while the CDC reports 7.4. For Merced and Tulare counties, where the CDC lists deaths as “NA” because fewer than 10 cases were reported each year, the new analysis suggests Merced averages 5.3 heat-related deaths annually and Tulare averages 11.1.

“If you had better numbers, you could also really argue [that] we need these preemptive investments, and there need to be more types of preemptive investments in heat,” Grace Wickerson, health equity policy manager at the Federation for American Scientists, told reporters.

The undercount happens because the doctors, coroners, and medical examiners who fill out death certificates often don’t consider whether heat played a role — even when someone with heart disease dies on a 100-degree day, or when a farmworker collapses in the fields during a heat advisory.

Fresno County pathologist Thomas Bennett, who performed an autopsy on 59-year-old Elidio Hernandez Gomez after Gomez collapsed picking tomatoes in August 2023, said he didn’t list heat on the death certificate even though it was 100 degrees that day and California’s worker protection department had issued a “high heat hazard” warning.

“It’s always hot in the valley,” Bennett said. “It was a classic heart-type sudden collapse in contrast to usual heat-related cases where they have nervous system changes and sweat profusely.”

Bennett, who is based in Las Vegas and works under contract with the Fresno Sheriff and Coroner’s Office, acknowledged heat could have contributed to Gomez’s death but questioned whether it should appear on the certificate. “Can you say that having heart problems predisposed him to having a heat-related death? Perhaps,” he said. “There will be opinions on both sides. As far as being able to prove it, good luck.”

The CDC itself has urged since 2017 that heat and other extreme weather be included on death certificates even when the role is indirect — when heat worsens an existing condition rather than causing death outright. The agency says its own tallies are likely severe undercounts.

But guidance is one thing; what actually gets written down is another. “Categorizing deaths is really kind of a halfway in between a science and an art,” said Dr. Kristen Sullivan, Merced County’s public health director. “We base our death counts for the county on death certificate data. It’s so dependent upon the medical person who is filling out the death certificate.”

Neither Fresno nor Kern County routinely tracks heat-related deaths on its own. Michelle Corson, spokesperson for the Kern County Public Health Department, said in a written statement that the department “does not routinely track heat-related deaths or other heat related outcomes.”

Fresno County’s Hope Megerdichian pointed to the county’s Heat Dashboard, which tracks emergency-department visits and shows about 40 heat-related paramedic calls in July of this year. “We are eager to review the study once it is published,” she said. “Once we have an opportunity to review, we may be able to provide additional insight.”

When officials don’t know the real number, they can’t respond as urgently as the situation calls for. After Oregon’s deadly 2021 heat dome killed 123 people — a toll officials didn’t learn until after the event — the state’s emergency director said if he’d known deaths were mounting in real time, “I just think about the people we could have saved if we had put the governor on TV saying that this heat is dangerous and we are investigating 25 deaths as possibly heat-related and we think that number will go up, and here is what you need to do.”

Oregon didn’t issue a statewide emergency declaration before that heat wave. Now it does.

In Maricopa County, Arizona — which includes Phoenix — officials investigate every death that happens when it’s hotter than 95 degrees, even indoors, and list heat on the death certificate whenever it could have worsened the condition that killed someone. That county recorded 2,113 heat deaths from 2018 through 2023, more than triple the prior six years — and more than California, Texas, Florida, and Louisiana combined over the same period.

Phoenix has used that data to redirect pandemic-era federal funds to cooling centers, pass laws protecting workers in high heat, and close hiking trails during extreme heat warnings after finding 14 percent of 2020’s heat deaths happened on trails or in the desert.

California has started conducting its own statistical studies comparing death rates during heat waves to normal periods. A September 2022 heat wave that broke Sacramento’s record by more than 6 degrees showed 20 deaths on official certificates — but the state’s own analysis found 395 additional deaths during that period, a fivefold difference.

That study also revealed Latino residents and people aged 24 to 64 saw the sharpest increases in death rates during the heat wave — not the elderly, whom officials often assume are most at risk.

Governor Newsom announced an Extreme Heat Action Plan in August aimed at helping California communities adapt to rising temperatures. All four Valley counties examined in the NPR/Boston University study have cooling centers available during extreme heat.

The Breakdown

• The CDC has reported an average of about 1,700 heat-related deaths nationally per year since 2018, but researchers estimate the real number is closer to 9,000.
• In Fresno County, researchers estimate 27.6 heat deaths annually versus the CDC’s 4.2; in Kern County, 23.3 versus 7.4.
• The undercount happens because doctors, coroners, and medical examiners often don’t consider heat when filling out death certificates — even when someone with a chronic condition dies on a dangerously hot day.
• The CDC has urged since 2017 that heat be listed on death certificates even when its role is indirect, but compliance varies widely.
• Neither Fresno nor Kern County routinely tracks heat-related deaths independently of death certificate data.

What This Means for You

The officials you elect — from county supervisors to the Governor to Congress — decide how much money goes toward cooling centers, heat warnings, and protections for outdoor workers. When they don’t know how many people are actually dying from heat, they can’t make informed decisions about where those resources need to go. Oregon didn’t issue an emergency declaration before its deadly 2021 heat dome because officials didn’t understand the danger; now, knowing the toll, it does. Your vote shapes who holds those offices and whether they treat heat as the public health crisis researchers say it is — or as something that’s “always hot in the valley” and not worth tracking closely.

What to Watch

Two questions this reporting raises: First, whose judgment are we trusting when a death certificate gets filled out? Fresno County contracts with a Las Vegas-based pathologist who openly questions whether heat that California’s own worker-safety department called a “high heat hazard” should be listed as a factor in a farmworker’s collapse. That’s not a scientific dispute — it’s a choice about what counts as worth documenting, and voters are entitled to ask whether the county’s contracting decisions are serving the public interest or just keeping the paperwork simple.

Second, why don’t Fresno and Kern counties track this on their own? Maricopa County, Arizona, does. California’s own Department of Public Health does statistical studies that catch deaths the certificates miss. Fresno County points to a dashboard tracking emergency-room visits — helpful, but not the same as counting who actually died. When county officials tell you they’re “eager to review” a study but don’t track the problem themselves, that’s a signal about priorities. Are they allocating resources to understand the scope of what’s happening, or waiting for someone else to tell them?