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In sun or shade, children are quickly unsafe in a hot parked car, study finds

Photo by Ryan Graybill on Unsplash
Tragically, 37 children die each year, on average, in the United States from being trapped in a closed, hot car.

With Minnesota in the midst of a heat wave, it’s a good time for parents, grandparents and anyone else driving around in a car with children to remember how dangerous it is to leave a child in a vehicle on a hot day — even when the car is parked in the shade.

Tragically, 37 children die each year, on average, in the United States from being trapped in a closed, hot car. This year has already seen at least seven children die, and summer — when the risk obviously climbs — has only just begun.

Three-quarters of children who die in a hot car are under the age of 2.

In more than half of these types of deaths, the parent or caregiver didn’t intend to leave the child in the car, but they became distracted and forgot the child was with them, usually because the child had fallen asleep in the back seat. Another significant portion of the deaths happened after unattended children climbed into a car and couldn’t get out.

Less than 20 percent of the cases involved a child being left intentionally in a car — while a parent did a shopping errand, for example.

Children die in heated cars due to complications of a form of hyperthermia known as heatstroke.  The child’s internal body temperature rises above 104 degrees Fahrenheit for an extended period of time. Unable to cool itself, the child’s body starts to shut down, quickly damaging the heart, lungs, brain, kidneys and other vital organs. 

The danger comes on quickly

The authors of a recent study, published in the journal Temperature, set out to determine just how long it takes for cars to reach temperatures fatal to children.


They placed six cars — two sedans, two economy cars and two mini-vans — outside on a summer day in Tempe, Arizona, when the temperatures were in the 100s. They then measured the interior temperatures of each car. After about one hour, the average air temperature inside the cars was 116 degrees Fahrenheit. The cars’ interior surfaces were also scorching hot: The temperature of the dashboards averaged 157 degrees and that of the seats, 123 degrees.

The researchers then repeated the experiment with the cars in the shade.  After one hour, the average interior temperature was 100 degrees Fahrenheit. The dashboards average 118 degrees and the seats, 105 degrees. 

In both cases, the economy cars warmed the fastest and the minivans the slowest due to differences in the air volume within the vehicles.

But none of the vehicles was safe for a child to be left inside it.

“We found that a child trapped in a car under the study’s conditions could reach a body temperature of 104 degrees F in about an hour if a car is parked in the sun, and just under two hours if the car is parked in the shade,” said Jennifer Vanos, the study’s lead author and an assistant professor of family medicine and public health at the University of California San Diego, in a released statement. “This body temperature could be fatal to infants and children — and those who survive may sustain permanent neurological damage.”

What parents can do

As Vanos and her colleagues point out in their paper, several technological solutions have been proposed to prevent these tragedies, such as having a sensor that alerts the driver if a child is still in the car when the driver gets out. But such solutions “have wavered due to industry disinterest, fear of sensor failure and liability, lack of market support, and cost,” the researchers explain.

So, it’s up to parents and other adults to be aware of the danger — and to take active steps to prevent it from happening to them. And don’t think your child is not at risk. As the nonprofit group notes, “Even the best of parents or caregivers can unknowingly leave a sleeping baby in a car; and the end result can be injury or even death.” 

Here are that organization’s safety tips above preventing heatstroke tragedies:

  • “Look Before You Lock”— Get in the habit of always opening the back door to check the back seat before leaving your vehicle. Make sure no child has been left behind. 
  • Create a reminder to check the back seat.

    * Put something you’ll need like your cellphone, handbag, employee ID or brief case, etc., in the back seat so that you have to open the back door to retrieve that item every time you park. 

    * Keep a large stuffed animal in the child’s car seat. When the child is placed in the car seat, place the stuffed animal in the front passenger seat. It’s a visual reminder that the child is in the back seat. 

  • Make sure you have a strict policy in place with your childcare provider about daycare drop‐off. Everyone involved in the care of your child should always be aware of their whereabouts. If your child will not be attending daycare as scheduled, it is the parent’s responsibility to call and inform the childcare provider. If your child does not show up as scheduled; and they have not received a call from the parent, the childcare provider pledges to contact you immediately to ensure the safety of your child. (This is very similar to the ‘absence‐line’ used by most elementary, middle and high schools.) 
  • Keep vehicles locked at all times, even in driveways or garages. Ask home visitors, childcare providers and neighbors to do the same. 
  • Keep car keys and remote openers out of reach of children. 
  • Never leave children alone in or around cars; not even for a minute. 
  • If a child goes missing, immediately check the inside passenger compartments and trunks of all vehicles in the area very carefully, even if they are locked. A child may lock the car doors after entering a vehicle on their own, but may not be able to unlock them. 
  • If you see a child alone in a vehicle, get involved. Call 911 immediately. If the child seems hot or sick, get them out of the vehicle as quickly as possible. 
  • Be especially careful during busy times, schedule changes and periods of crisis or holidays. This is when many tragedies occur. 
  • Use drive‐thru services when available (restaurants, banks, pharmacies, dry cleaners, etc.) and pay for gas at the pump. 

FMI: You’ll find an abstract of the study on Temperature’s website, but the full study is behind a paywall. 

Comments (1)

  1. Submitted by Pat Berg since 2011 on 05/29/2018 - 09:42 am.

    Starting temperatures?

    Do you know what outdoor temperatures they looked at besides 100F? Specifically, do you know what temperatures BELOW 100F were studied, and how much below?

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