Things to Know About Heat Deaths as a Dangerously Hot Summer Approaches in the Western U.S.

PHOENIX — A dangerously hot summer is brewing in the western US, with heat suspected in dozens of recent deaths, including retirees in Oregon, a motorcyclist in California’s Death Valley and a 10-year-old boy who collapsed while walking with his family on a road. Phoenix Trail.

Heat is the leading cause of weather-related deaths across the country. But because investigations into suspected heat deaths can take months, and a confusion of methods is used by counties to count them, it is not known exactly how many people died in the recent heat wave that began on July 1.

There are indications that these were two especially deadly weeks.

“This is just a harbinger of things to come,” Joellen Russell, a climate scientist at the University of Arizona in Tucson, said Friday. “The floods, the droughts, the wildfires, the heat waves, the hurricanes, the storms: we trigger all this extreme weather with the extra carbon dioxide we put into the atmosphere.”

Here are some things you should know:

Nineteen deaths are being investigated for possible heat-related causes in Santa Clara County in Northern California, where a heat wave this month sent temperatures into the triple digits. The medical examiner’s office said four people who died were homeless and nine were over the age of 65.

At least 16 people are suspected of having died due to record high temperatures in Oregon, mainly in the Portland metro area.

There have been nine confirmed heat-related deaths this year in Clark County, Nevada, which encompasses Las Vegas, the county medical examiner’s office said.

Several recent deaths being investigated in Arizona involved young children, including a 2-year-old girl who was left alone in a hot vehicle outside Tucson and a 4-month-old child who died after falling ill while on a boat on Lake Havasu.

High temperature records were broken in western states this month, with Palm Springs, California, reaching its peak. all time high of 124 Fahrenheit (51.1 Celsius) on July 5 and Las Vegas recording its all time high of 120 F (48.8 C) on July 7.

Las Vegas recorded a record seven consecutive days of 115 F (46.1 C) or higher during the recent heat wave, nearly doubling the old mark of four consecutive days set in July 2005, the National Weather Service said. The city has recorded at least 18 heat records since June 1st.

California’s Death Valley recorded a high of 129 F (53.8 C) on July 7, tying the daily record set in 2007, according to the National Weather Service. The high in Phoenix reached 115 F (46.1 C) on Wednesday, tying the Daily record set in 1958 and 1934.

Portland, Oregon set new daily records five days in a row until Tuesday, when it hit 104 F (40 C).

The number of victims of the scorching heat is unknown due to the various ways jurisdictions use to calculate these deaths. But some southwestern counties do a better job than the majority of the county.

Pima CountyArizona’s second-most populous county and home to Tucson, last year began including heat-related deaths in a new online dashboard. Maricopa County, home to Phoenix, the hottest major city in America, has been monitoring heat-related deaths for years. Clark County, Nevada, where Las Vegas is located, now also identifies deaths in which heat was a contributing factor.

But the count of heat-related deaths in most jurisdictions is inconsistent. Death investigations in some places are carried out by a coroner, typically a doctor trained in forensic pathology. In other places, the coroner could be an elected sheriff, as in Orange County, California. In some small Texas counties, a justice of the peace can determine the cause of death.

Even the Centers for Disease Control and Prevention’s numbers are often several years behind in reporting and offer an incomplete picture because they rely on information from death certificates pulled from local, state, tribal and territorial databases.

An Associated Press analysis of CDC data from this year found that the death certificates of more than 2,300 people who died in the U.S. last summer mention the effects of excessive heat, the highest number in 45 years of records. Doctors, public health experts and meteorologists say that’s just a fraction of the true number.

In some cases, pathologists can take months to determine whether the death was heat-related.

Unlike a suicide by hanging or a homicide caused by a bullet to the head, a heat-related death is not always easy to determine. It may take weeks, or even months, of toxicology tests to determine whether heat was a factor.

There’s a lot of ambiguity for investigators to sort through when a body is found in a hot apartment days after a death. Although it may have been very hot when the person was found, it is impossible to know how hot it was inside a residence when the death occurred.

Toxicology tests can also take a long time to determine substance use, such as alcohol or illicit drugs.

Because of this delay, it wasn’t until this spring that the Maricopa County Department of Public Health was able to release its final count of 645 heat-related deaths in 2023. The deaths included those in which heat was a secondary factor, such as a heart problem. attack caused by high temperatures.

Temperatures in Portland, Oregon, cooledbut it is expected to warm slightly over the weekend, with highs in the 90s, extending as far south as Salem and Eugene.

The National Weather Service in Phoenix said an excessive heat warning was forecast will continue through Saturday, with highs reaching 111 F (43.8 C) before falling below 110 F (43.3 C) on Sunday and into next week.

After 10 days under an excessive heat warning, Las Vegas was expected to have slightly cooler weather over the weekend. Still, highs next week are forecast to remain above normal, ranging from 110 to 112 F (43.3 to 44.4 C), the National Weather Service said.

And summer isn’t over yet.

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Associated Press writers Rio Yamat in Las Vegas and Claire Rush in Portland, Oregon, contributed to this report.