Since 1998, about 450 children in the U.S. have died of hyperthermia after being trapped in cars

Story highlights

37 babies and toddlers die of hyperthermia each year when accidentally trapped in vehicles

Causes include hot cars in warm weather and excessive clothing in cooler weather

Most cases result from parents simply forgetting their children are in the car

Parenting  — 

Each year about 37 babies and toddlers die when they are accidentally left strapped in car safety seats or become trapped in vehicles that rapidly heat up.

If you think this senseless tragedy couldn’t happen to you, think again.

Mary Parks and her husband, Jeff, had everything they wanted: a comfortable house in Blacksburg, VA; well-paying jobs (Parks was an accountant, Jeff a research scientist); and two darling boys adopted as babies from Guatemala.

The end of August and start of September 2007 had been stressful, though. Twenty-three-month-old Juan and his 4-year-old brother, Byron, had both been sick on and off. Parks’s days had been blurs of work, daycare, doctors, business trips, visits with relatives, and anxiety. On September 7, after attending to a feverish Byron the night before, she left him home to recuperate with Jeff. Her plan was to drive Juan to daycare on her way to work.

Parenting.com: Shocking Pool Safety Hazard

Rarely had Parks taken just one boy to daycare. Rarely had she gone to work at all if one boy was sick – but this time she and Jeff agreed to swap roles. Moments after she started driving, Parks says, she realized Juan had fallen asleep. It was the last time that morning that she would remember he was in the car.

“We were no longer taking anything of his to daycare – we were beyond diaper bags,” she says. So there was no baby gear in the front seat to remind her. She caught no glimpse of him in the rearview mirror, either; in his car seat, Juan was too short to spot easily. Most important, perhaps, Byron wasn’t there, chattering away. “He never fell asleep in the car,” Parks explains.

Instead of stopping at the daycare center, she drove right to work. Parks grabbed her purse from the front seat, went into her office, and had “a normal day.” Talked with her supervisor. Ate lunch at her desk. Called Jeff to see how Byron was doing. She even remembers telling colleagues that – since Juan had been sick, too – she might have to leave early if a call came from daycare to get him. In her mind, that’s exactly where he was.

Parenting.com: 12 Hot Outdoor Toys

After work, Parks drove to the supermarket, shopped for dinner, and continued on to the daycare center to pick Juan up – unaware that he was already sitting right behind her. When she arrived, his teacher asked, “Was Juan out sick today?”

“No,” said Parks. “I brought him this morning.”

“He wasn’t here today,” the teacher said.

Within moments, Parks recalls, “a light in my head went on. I took off running toward the car. My heart was already in my feet because I knew how hot it had been that day. I got to the car, jerked open the door, and saw him. I reached over to him. I remember screaming at him, ‘Juan! Juan! You’ve got to wake up!’?” Cradling her son’s body – stiff and still as a baby doll’s – Parks ran inside the daycare office. One staffer tried desperately to revive Juan with CPR; another called 911. “I went in crying for help,” Parks says, “but I knew he was dead.”

Parenting.com: The Dark Side of Family Travel

A heart-wrenching epidemic

What happened to Juan that day – death by hyperthermia, caused when the body’s temperature rises uncontrollably – has happened to about 450 children in the U.S. since 1998. “It’s reasonable to call this an epidemic,” says memory expert Dr. David Diamond, a scientist at the Veterans’ Hospital in Tampa, who is often consulted on such cases. “It happens, on average, once a week from spring to early fall.”

Babies and young children are not able to regulate their body temperatures well – warming at a rate three to five times faster than an adult – especially in a car, where the windows create a greenhouse effect. In just half an hour, a car’s interior can get 35 degrees hotter. Depending on such factors as what color he’s wearing and when he last drank something, an infant might die of hyperthermia in just 15 minutes on a 75-degree day.

Cooler weather is no guarantee of safety, either. Overly bundled babies – warmly dressed and blanketed in their car seats – have been known to succumb when outdoor temps were in the 60s or even 50s. And despite popular belief, cracking open a window does little good. That tiny bit of air can’t begin to offset the heat that is absorbed by a car’s seats, dashboard, and walls.

Parenting.com: The Danger of Dehydration

Some children are knowingly and negligently left inside hot vehicles while their parents do errands. Other kids climb inside their parents’ parked cars and become trapped. But most, like Juan Parks, are victims of adults’ disastrous lapses in memory. “Given the right scenario, I would say this can happen to anyone,” says Diamond. “It has nothing to do with how much parents love their kids. It is, to me, a tragic way of learning how the brain works.”

Each of us has dueling memory systems, Diamond explains. The first – in the primitive, “reptilian” part of the brain – directs our habits. It’s the system that lets you drive home from work without thinking consciously about every turn. The second system – located in more advanced brain regions – is responsible for short-term plans, such as “Buy milk on the way home.” And as anyone who has ever forgotten that milk knows, the primitive “habit system” is much more powerful. “It’s very difficult to keep in your mind that you want to override your habit system,” Diamond says. “And it can take over almost immediately.”

Parenting.com: Protect Yourself from Summer Heat

Of course, forgetting a child is far different from forgetting a gallon of 2%. But not to the reptilian brain. Imagine that your plan is “Drop kid at babysitter’s on the way to work.” If you’re tired or distracted by worries, or – worse – if you’re not the person who usually takes the kid to the sitter’s, your habit system can erase that plan with appalling ease. Like Mary Parks, you go straight to work on auto-pilot, spacing out on the fact that your child is with you in the backseat. You even develop false memories of dropping him off. “The brain is very good at filling in gaps, so you will remember what you assume you did,” Diamond says.

Ironically, hot-car deaths have become much more common thanks to practices meant to protect young passengers: placing them in the backseat and positioning infant seats to face backward. These precautions, which became standard in the 1990s, are important to follow because they shield babies and small kids from airbags and other hazards. But they can also put them “out of sight, out of mind.”

Diamond knows this first-hand. One day last year, he forgot that his baby granddaughter was in the car with him during a drive to the mall. (She normally would not have been.) “I could have walked around that mall for hours, having absolutely no recollection that she was in the car,” Diamond says.

Fortunately, his wife was with him, too, and remembered to get the baby out. Experts suspect there are thousands of such “almosts” each year. But few of those stories become public – making it easier for the rest of us to jump to damning conclusions when tragedies like Parks’s hit the news.