Heatstroke Deaths of Children in Vehicles
Frequently Asked Questions

Jan Null, CCM
San Jose State University

1.  How did a meteorologist get involved in studying and tracking heatstroke deaths of children?

2.  How are the statistics gathered? How accurate are they?

3.  Why are some incidents labeled as "probable?

4.  Isn’t there technology that will warn us if a child is left in a vehicle?

4a. What if the government mandated that every new car be equipped with a reminder device of some kind. Wouldn't that solve the problem? Updated 09/18/2016

5. How are temperatures properly measured inside a vehicle?

6.  How hot do objects that are inside a car and in direct sunlight get?

7.  How much hotter does it get inside a trunk that inside the passenger compartment?

8.  How can I use your statistics on my own website?

 1.  How did a meteorologist get involved in studying and tracking hyperthermia deaths of children?

On July 24, 2001 a young father in San Jose, CA left his 5-month old son in the car on an 86 degree day while he visited friends.  Two hours later he came out and Kyle Patrick Gilbert was dead.  At that time I was asked by the media “how hot get in that car?” and the only study I could find was from 1993 in Louisiana and only looked at a single 93 degree day.  Out of scientific curiosity I started casually tracking temperatures in my own vehicles and was startled at not only how hot the readings were but also how rapidly they rose.  The following summer I a more controlled study and the project grew from there.  I began working with some of the child car safety groups to share my data and also link it to their case data.  About the same time I started working with two Stanford University Hospital Emergency Medicine doctors who became my co-authors for an article in the Pediatrics. Once it was published it became the “go to” article on the topic and is used worldwide.  My hopes are that this research will raise the level of interest and awareness about this sad topic and ultimately to save some innocent lives.

2. How are you statistics gathered?  How accurate are they?

Our statistics are primarily gathered with customized online news searches of electronic media using tools such as Google News and Lexis-Nexus. Rarely, we become aware of a fatality that somehow never caught the attention of local media, happened in a locale without electronic media or occasionally were suppressed by the families or local authorities.

Even so, we have found that using electronic news sources yield nearly twice as many reported heatstroke deaths of children in vehicles as did official sources. For example, the latest (March 2015) National Highway Traffic Safety Administration (NHTSA) Not-in-Traffic Surveillance (NiTS): Non-Crash Fatalities and Injuries report, based on death certificates from the special mortality files of the National Vital Statistics System (NVSS), estimated an annual average of only 19 fatalies of children (i.e., <14 years) due to hyperthermia in vehicles. From tracking of media reports there were 112 deaths documented in that same 3-year period; an average of 37 per year.

3.  Why are some incidents labeled as "probable?

It often takes a number of days or weeks for officials (i.e., police, prosecuter, medical examiner) to gather information to make an offical determination that the cause of death was heatstroke.  However, when circumstances are such that there will probably be a determination of heatstroke then it is my opinion that public awareness of the death of a child unattended in a vehicle is important.

4.  Aren't there technological or other products that will remind or warn us if a child is left in a vehicle? 

Yes, there are technological answers and I applaud them and every live that they might save. They range from simple visual reminders to extremely complex technologies.  I get a several inquiries a month from potential inventors/developers who have a "solution", most of them quite brilliant.  But to date there are very few "devices" on the market and their market share and impact appears minimal at best.

It is especially important to note that these types of sensors/devices are aimed at the segment of the cases where a child is accidently forgotten (54%), but not the other half of the cases where children gain access on their own or are intentionally left in vehicles. 

National Highway Traffic Safety Administration (NHTSA) commissioned a 2012 study by Children's Hospital of Philadelphia (CHOP), Reducing the Potential for Heat Stroke to Children in Parked Motor Vehicles: Evaluation of Reminder Technology, that seriously questioned the reliability of the products it tested. Subsequently in 2015 NHTSA published Functional Assessment of Unattended Child Reminder Systems.

To keep the overall effectiveness of a technological solution in context, assume a 100% foolproof device could be magically installed in 10% of the 50 million cars, trucks, SUVs and vans that carry children on the highways of the United States.  This wildly optimistic scenario would only save about 5% (i.e., 10% of 54%) of the forgotten child heatstroke deaths that have occurred!  That is, only a tenth of the 54% of the deaths where a child was accidently left in a vehicle, or less than two lives per year. 

And this does not factor in the problems of getting devices to market, liability issues, getting shelf space (or virtual shelf space for online sales) and more importantly getting people to buy the device.  Child safety experts say that the most common response from a parent is "I don't need one of those; I would never forget MY child!"  Not to mention the huge question of whether technological answers, mandated or not, will leave out underserved populations with literally millions of used cars and used car seats in circulation.  And there is the issue of liability that a retailer, or others selling these type of devices, might incur if a device proved not to be reliable.

Every life that is saved is a blessing but the bottom line is that technology is only a small part of the solution and not the "panacea" it is often touted to be in the case of heatstroke deaths of children in vehicles.

Important Note:  I do not endorse or link to any products as I have no way to properly evaluate or vet them, and to do so would take an inordinate amount of my time and resources.

4a. What if the government mandated that every new car be equipped with a reminder device of some kind. Wouldn't that solve the problem?  Updated September 18, 2016

Again, if lives are saved great. But it must be kept in mind that the main focus of "devices" would be toward only the 54% of the cases where a child is forgotten; thus not a solution for the other 46% or 17 of the average 37 lives lost per year.

And it is also not close to a panacea if one "does the math". There are approximately 260 million cars and light trucks (i.e., SUVs, vans and pickups) on the roads in the United States. In recent years, approximately 17 million of these vehicles have been sold each year.  At this rate it would take over 15 years for all the vehicles to be turned over; not taking into account that people are keeping vehicles longer and the total numbers are increasing.  Thus in the 10th year after implementation, only about 65% of the vehicles would have "devices" meaning only 34% (i.e., 65% times 54%) of the average 37 lives, or about 13, would be saved. And 24 would not!!

Looking at the entire 10-year period as devices were phased in at a rate of 17 million vehicles per year, the total number of lives saved would be about 72, while 298 would still be in jeopardy; or about 19%.  And like above, the numbers would leave out a greater percentage of the poorer segments of the population that do not replace vehicles at the same rate as more affluent members.

Note: On September 15, 2016 a bill has been introduced in the US House of Representatives (HR 6041, A HOT CARS Act) that, if passed, would direct that all NEW passenger vehicles be equiped "with technology to provide an alert that a child or unattended passenger remains in a rear seating position after the vehicle motor is deactivated."

5.  How are temperatures properly measured inside a vehicle?

The temperature inside a vehicle should be taken the same way as it is outdoors; and that means NOT in direct sunlight.  When a thermometer is exposed to the sun you are then measuring the energy of the sun and not the temperature of the air.  In the research associated with this study, the temperature readings were taken with a thermometer suspended in free air (i.e., not directly in contact with objects in the vehicle), at approximately the same level as a car seat and out of direct sunlight.  Readings should also be taken with either a remote thermometer or one that can be read without opening the vehicles doors.

6.  How hot do objects that are inside a car and in direct sunlight get?

While taking air temperature measurements I also regularly used an infrared thermometer to measure the surface temperatures of objects inside the vehicle.  On days when the ambient outside air temperature was in the 80’s it was common to see the temperature of a dark dashboard or steering wheel to be 180 to 200 degrees.  Even outside, the temperature of a black asphalt parking lot surface will exceed 160 degrees.

7.  How much hotter does it get inside a trunk that inside the passenger compartment?

Surprisingly the inside of a trunk is cooler than the inside of the car itself.  This is because most the heating occurs from objects being heated by sunlight and those in turn heating the air.  Since no sunlight gets into the trunk the temperatures are cooler.  During my research I anecdotally took some temperature reading inside the trunk on my test vehicle and they were about 5-10 degrees cooler than the air in the passenger compartment.

8.  Can I use your statistics from your website?

Yes, the information and statistics from this website ( http://noheatstroke.org ) may be used if full attribtution is given to the source. Please cite as: "Source:  Jan Null, CCM, Department of Meteorology and Climate Science, San Jose State University, http://noheatstroke.org". A live link back http://noheatstroke.org is preferred as data on the site changes frequently and this ensures that users can gain access to the most accurate and up-to-date information.

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  Questions, comments or suggestions.  Email jan.null@sjsu.edu
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Jan Null, CCM 
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