Hot car deaths: Why they happen and how to prevent them

Hot car deaths in children are often misunderstood. They typically peak in the summer, yet "this is not just a summertime issue," pediatrician Dr. Harvey Karp, founder and chief executive officer of Happiest Baby, tells Yahoo Life. Heatstroke from a child unintentionally being left in a car or getting into an unattended vehicle on their own is a year-round problem in several areas throughout the country.

What most people struggle with, however, is how a parent could unknowingly leave a child in a car. But experts say it could happen to anyone.

"Child hot car deaths and injuries are largely misunderstood by the general public," Janette Fennell, founder and president of KidsandCars.org, a national nonprofit child and pet safety organization, tells Yahoo Life. "The majority of parents and caregivers are misinformed and would like to believe that they could never 'forget' their child in a vehicle. The most dangerous mistake a parent or caregiver can make is to think leaving a child alone in a vehicle could never happen to them or their family. In over half of hot car deaths, the person responsible for the child's death unknowingly left them in the vehicle."

Fennell says it can be "very difficult" for people to accept important information about hot car dangers "because people don’t think these messages apply to them." But, she adds, "In an overwhelming majority of child hot car deaths, it was a loving, responsible parent that unknowingly left the child."

Here's what parents and caregivers need to know about hot car deaths and how to prevent them.

What's the most common age for hot car deaths?

Hot car deaths in children have risen over the years. According to the National Highway Traffic Safety Administration, about one child dies of heat stroke ever 10 days after being left in a hot car.

They can happen when a parent unknowingly leaves a sleeping child in a car or when small children get trapped in an unattended vehicle on their own, such as when it's parked in the family's garage or driveway.

The vast majority (87%) of hot car deaths in children occur in those age 3 and younger, according to Fennell. Of those, 54% involve children age 1 and younger. "Rear-facing child safety seats do not look any different to the driver if they are occupied or empty, which can cause a parent to think the child is no longer in the car with them," explains Fennell.

The majority (68%) of children who gain access to an unattended vehicle on their own are male and most are 1 to 4 years old, according to Fennell.

Why hot cars are so dangerous for kids

Because babies' and young children's bodies are still developing, they don't react to heat the same way adults do, explains Karp.

"A child can overheat up to five times faster than a grownup," he says. "That's because young children, and especially babies, have extra fat under the skin — that acts like an insulating blanket — and they have less skin surface to allow sweating and loss of body heat. Therefore, they simply have great difficulty dealing with excessive heat."

He adds: "Plus, babies and little kids dehydrate more quickly than adults."

It's easy to underestimate how hot it can get inside a car

Even if it's not hot outside, temperatures can still climb dangerously high in a car, even with the windows cracked open. Fennell points out that "we have documented hot car fatalities when the temperature outside has been as low as 57 degrees."

Karp explains that "because adults are better able to regulate their temperature — and we can open a window, turn on the A/C or cool down with a drink of water — it's easy to forget how dangerous a hot car can be for little ones. Even with the windows cracked, the temperature inside a vehicle can reach 125 degrees Fahrenheit in minutes!"

He explains that the dark interior of a car and lack of ventilation can create "dangerous levels of heat, even when the outside temperature is moderate," adding: "In fact, research shows that the temperature inside a closed vehicle can shoot up to over 100 degrees within an hour when it’s just 61 degrees Fahrenheit outside."

How to prevent hot car deaths

The key to preventing these deaths, says Fennell, is technology, education and awareness.

Starting with General Motors in 2017, some car manufacturers offer a rear seat reminder system with certain models. If a car's rear door is opened — presumably to let in a child, pet or perishables — the car will alert the driver to check the back seat once the car is parked and the engine is turned off. But Fennell says the system doesn’t detect whether an infant or child is actually in the car. "It only lets you know that you opened that back door," she says.

Some car manufacturers are adding more targeted safety features to alert drivers about children and even pets in the back seat. For example, Toyota's "cabin awareness" technology uses a 4D imaging radar sensor to detect people and pets in the car — even picking up on “micro movements, such as a heartbeat, motion and respiration of occupants."

In the meantime, there are low-tech steps parents and caregivers can take to keep their children safe. Fennell recommends making it a habit to open the back door — not just turn around to look while you're sitting in the driver's seat — and check the back seat when you arrive at your destination. "It takes three seconds to make sure nobody's left behind," she says.

Another option is to place something important in the back seat, such as your handbag, laptop or employee badge, keeping it out of reach so you have to open the back door to get it. Or Fennell says a parent could place a stuffed animal, such as a teddy bear, in the child's car seat. "When the baby is in the car seat, move the stuffed animal to the seat up front," she says. "If the bear is up front, the baby is in the back."

She also suggests making a plan with your child care provider that you will call if you're not dropping off your child that day. If the child isn't dropped off and there’s no phone call, you can ask the child care provider to call an emergency number. If this were a more common practice, "one phone call literally could have saved hundreds of lives," says Fennell.

Because nearly a third of hot car deaths involve children getting into vehicles on their own, Fennell recommends keeping cars locked at all times, especially in the garage and driveway. People might be more inclined to relax about locking the car when it's parked at home, "but that's where they get the keys," says Fennell, who notes that kids can push the button to unlock the car "because they've seen you do it so many times. Don't leave your keys within reach of children."

Fennell also recommends teaching young children that if they do get stuck in the car, they should honk the horn for help.

If a child is missing, experts say it's important to immediately check any nearby body of water, such as a pool, first and "then you need to check the inside of the car — I mean the floorboards, the trunk, all around," says Fennell.

What should you do if you see a baby or young child unattended in a vehicle?

If you see an infant or child alone in a vehicle, experts suggest getting involved. "Call 911 immediately," says Fennell. "If the child seems hot or sick, get them out of the vehicle as quickly as possible."