This collection of research on child deaths in hot cars, originally published in June 2017, was updated on June 25, 2025 with new data and reports on pediatric vehicular heatstroke.
Dozens of U.S. children die every year after being left alone in parked cars, where temperatures can rise rapidly even on cool days. In recent months, news outlets have chronicled the deaths of at least seven youngsters, including a 7-month-old girl in North Carolina whose foster mother was charged this month with involuntary manslaughter after allegedly leaving the infant in a minivan “for an unknown period of time.”
Reports of pediatric vehicular heatstroke were on the rise even before a dangerous heat wave began blasting most of the eastern U.S. this week, driving temperatures to record levels in Baltimore, Boston, Newark, Raleigh and other major cities. Last year, 39 youngsters died after being left in hot cars, up from 29 in 2023, according to the National Highway Traffic Safety Administration.
In many states, it’s illegal to leave children unattended in a vehicle. But parents, grandparents, daycare providers and other caregivers sometimes forget about them. Sometimes, adults leave kids behind not realizing that a child’s body temperature rises three to five times faster than an adult’s or that rolling down a window or parking in the shade does little to cool the interior of a vehicle.
“It doesn’t have to be very hot outside for a vehicle to reach deadly temperatures inside,” meteorologist Jan Null, who researches child heatstroke deaths, wrote on social media in May. “It was only a 68° day when the first hot car child death of 2025 occurred.”
Null’s website, NoHeatStroke.org, tracks child deaths in hot vehicles back to 1998. Because of a lack of standard reporting procedures, NoHeatStroke.org and the nonprofit organization Kids and Car Safety provide the most complete data on the topic, researchers note in an academic paper published last year in the journal Traffic Injury Protection. News outlets can use Null’s charts and analyses in their reporting, provided appropriate credit is given.
Data he collected from 1998 to 2024 show:
- Almost three-fourths of children who died of vehicular heatstroke, also known as vehicular hyperthermia, were 2 years old or younger.
- Although 53% had been forgotten in parked automobiles, 24% got into a vehicle on their own.
- The 10 states where pediatric vehicular heatstroke was most common are Alabama, Arizona, California, Florida, Georgia, Louisiana, North Carolina, Tennessee, Texas and Virginia.
To help journalists better understand and cover this topic, we gathered research that examines vehicular heatstroke from different angles. Below are summaries of academic studies and government reports that look at how often caregivers are prosecuted after a child dies, how automobiles contribute to heatstroke, problems with heatstroke data, the psychological processes that can prompt otherwise attentive parents to forget infants in parked cars, and more.
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A close look at estimates of child deaths
Pediatric Heatstroke Fatalities Caused by Being Left in Motor Vehicles
Deborah L. Hammett, Thomas M. Kennedy, Steven M. Selbst, Amber Rollins and Janette E. Fennell. Pediatric Emergency Care, December 2021.
Researchers analyzed 541 cases of children dying after being left in hot vehicles from Jan. 1, 2000 to Dec. 31, 2016, 528 of which involved one child and 13 of which involved two or more. Deaths were documented in 45 states. Most were accidental and occurred in home driveways and apartment complex parking lots. The authors find that heat-related deaths rose over the course of their 26-year study period. They also note authorities pursued criminal charges in 58% of cases.
Retrospective Analysis of Heat Stroke Deaths of Children in Motor Vehicles
National Center for Statistics and Analysis. Traffic Safety Facts Research Note, December 2015.
This report explains why the numbers the National Center for Statistics and Analysis releases for heatstroke-related deaths are generally lower than what is reported by other sources. The federal agency collects information from death certificates, which differ in how they describe children’s cause of death. For children who died of suspected heat stroke, the cause of death is sometimes listed as “fever, unspecified” or “assault (homicide) by other specified means” or “neglect and abandonment.” These children would not be included in the center’s tally of child deaths in hot cars.
Hyperthermia Deaths Among Children in Parked Vehicles: An Analysis of 231 Fatalities in the United States, 1999-2007
John N. Booth III, Gregory G. Davis, John Waterbor and Gerald McGwin Jr. Forensic Science, Medicine, and Pathology, March 2010.
This paper is one of the first to examine the characteristics of kids who died after being left in parked cars. Researchers gathered data from the U.S. Centers for Disease Control and Prevention on children whose cause of death was classified as exposure to excessive natural heat. Researchers focused on children aged 14 years and younger who died between 1999 to 2007 and cross-checked that data with other sources, including news articles and Null’s database.
The paper provides a range of details about these children and the circumstances of their deaths, including who was responsible for their care at the time, how long they were left unattended and their core body temperatures when they were discovered in vehicles. Of the 231 cases reviewed, 25% involved children who got into vehicles while playing.
Understanding parent, caregiver forgetfulness
When a Child Dies of Heatstroke After a Parent or Caretaker Unknowingly Leaves the Child In a Car: How Does It Happen and Is It a Crime?
David M. Diamond. Medicine, Science and the Law, March 2019.
In this journal article, David Diamond, a professor of psychology, molecular pharmacology and physiology at the University of South Florida, explains how human memory works, factors that contribute to memory failure and why loving, attentive parents and caretakers sometimes forget young children in hot vehicles. “Just as a detective can forget his weapon in a public bathroom and a pilot can forget to set the wing flaps properly prior to take-off, a parent or caretaker can forget a child in a car, which puts the child at risk of harm from heatstroke,” Diamond writes. He also explains why he thinks a person who unknowingly and unintentionally left a child in a car should not be charged with a crime.
How automobiles contribute to heat stroke
Impact of Dangerous Microclimate Conditions within an Enclosed Vehicle on Pediatric Thermoregulation
Andrew Grundstein, Sarah Duzinski and Jan Null. Theoretical and Applied Climatology, January 2017.
This study demonstrates how children left for just minutes in a parked vehicle can be severely injured or die. Researchers simulated a child’s physiological response to being left in an enclosed automobile at varying temperatures and levels of sun exposure. They find that children can suffer heatstroke in less than an hour when the starting temperature inside a vehicle is about 79 degrees Fahrenheit. They can suffer heatstroke in less than 15 minutes when cabin temperatures start at about 115 degrees Celsius or higher.
Heat Stress from Enclosed Vehicles: Moderate Ambient Temperatures Cause Significant Temperature Rise in Enclosed Vehicles
Catherine McLaren, Jan Null and James Quinn. Pediatrics, July 2005.
Researchers measured how much and how quickly temperatures rise inside an enclosed automobile, even when windows are cracked open. They measured the rise in temperature inside a dark sedan on 16 clear, sunny days when ambient temperatures ranged from 72 degrees Fahrenheit to 96 degrees Fahrenheit. Their main takeaways: The temperature of the car’s interior heated rapidly and most of the increase occurred within the first 15 to 30 minutes.
“Regardless of the outside ambient temperature, the rate of temperature rise inside the vehicle was not significantly different,” researchers write. “The average mean increase was 3.2°F per 5-minute interval, with 80% of the temperature rise occurring during the first 30 minutes. The final temperature of the vehicle depended on the starting ambient temperature, but even at the coolest ambient temperature, internal temperatures reached 117°F.”
The image above was obtained from the Flickr account of Joseph Novak and is being used under a Creative Commons license. No changes were made.
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