3 young children die in hot cars across the U.S.

Three young children died in recent days after they were found unattended in vehicles in Washington state, Texas and Florida, authorities said.

The fatalities boosted the number of hot-car deaths for children this year to six, double the number at this time last year, according to Jan Null, a California meteorologist who tracks the incidents.

Police in Puyallup, Washington, a city just southeast of Tacoma, were investigating the death of a 1-year-old who was left in a vehicle parked at a hospital while the child's foster mother worked, they said Tuesday.

The woman discovered the child in the car about 5 p.m. last Wednesday after roughly nine hours, Puyallup Police Capt. Don Bourbon said. She immediately took the child to the hospital, but the child died, he said.

NBC affiliate KING of Seattle reported the vehicle was parked at MultiCare Good Samaritan Hospital in Puyallup.

'It’s horrifying'

Police have suggested it was a mistake, with the foster mother distracted enough that morning to forget the child was with her, Bourbon told KING.

“It’s horrifying not only for the family but anyone who’s involved in a child’s death,” Bourbon told NBC News.

National Weather Service meteorologist Samantha Borth said high temperatures in the region were in the low 70s last Wednesday. Researchers concluded years ago that even a 70-degree day could result in deadly triple-digit temperatures inside a car as it acts like a greenhouse.

In Houston, where temperatures reached the high 80s over Memorial Day weekend, police said they were investigating the death of a 4-year-old boy who was found in an unlocked parked car with a 2-year-old girl about 4:30 p.m. Friday, according to a statement.

Both were rushed to a hospital, where the 4-year-old was pronounced dead, police said. The 2-year-old was expected to recover, it said.

An adult found the children, who had been playing outside their home, in the vehicle with at least one of the children reported to be unconscious, police said.

In Palm Bay, a city on Florida's Atlantic coast, an 11-month-old was discovered unresponsive early Sunday afternoon after having spent three hours unsupervised in a parked vehicle, city police said in a statement Tuesday.

'This is an unfortunate incident'

The parents had been attending church services, the police department said. The incident was under investigation, it said.

"This is an unfortunate incident," Chief Mario Augello said in a statement from the department, "and our condolences and prayers go out to the family."

High temperatures in the area Sunday were at or near 80, according to National Weather Service data.

The U.S. Climate Prediction Center has said there's a greater likelihood, compared to equal chances, that warmer-than-normal temperatures will be experienced in much of the country through the end of August.

Those areas include the locations of the late-May deaths: the Pacific Northwest, Texas and Florida.

Hot-car deaths by heatstroke are the leading cause of non-crash vehicle deaths for children under 14, according to the U.S. Transportation Department.

Children who die in hot cars usually do so because rapidly rising temperatures cause heatstroke. A vehicle’s temperature can spike 40 degrees in an hour, according to a Stanford study co-authored by Null, who tracks hot-car deaths on his website NoHeatStroke.org.

'Hot car death season'

Likewise, children’s core temperatures rise fast — three to five times faster than adults’ — with heatstroke settling in with a body temperature of 104 and death at 107, according to a fact sheet distributed by the Transportation Department.

The organization Kids and Car Safety calls this time of year, from late May to summer's end, "hot car death season" and says the transition to a new season can bring households new routines that can distract and disorient parents.

"A change in the normal daily routine and fatigue are the most common contributing factors for a child being unknowingly left behind in a vehicle," the organization said in a statement Tuesday.

The Transportation Department says the number of child hot car deaths went down in recent years as a result of the pandemic's impact on the number of people working from home.

In 2020 and 2021, the annual numbers for child deaths in hot cars — 25 and 23, respectively — were each less than half the figure for 2019: 53. In total, 33 such deaths were reported last year, according to NoHeatStrokeDeath.org.

The numbers are not encouraging, because at this time last year, three deaths had been reported, Null said. It's a sign the nation is returning to post-pandemic normalcy, he said.

The best preventive measure, experts say, is to develop routines that always take children into account, even if they're out of school, overseas or at a grandparent's house.

Null recommends placing a teddy bear on the front passenger seat when children are in the back. And he said drivers should place items such as briefcases and bag lunches in the back seat so they'll have to look there when they arrive at work.