Hyperthermia Deaths of
Children in Vehicles

by Jan Null, CCM
Adjunct Professor of Meteorology, SFSU

Updated April 29,  2008


FACT SHEETSEnglish, Español
[Note: This study has now been published in
Pediatrics. Click
here to download ]

Already in 2008 there have been at least four deaths of small children after being left inside a hot vehicle.  Last year there were a total of at least thirty-five such fatalities in the United States due to hyperthermia after they were left in hot cars, trucks, vans and SUV's.  This sadly followed 42 and 30 child deaths in 2006 and 2005 respectively.  Since 1998 there have been at least a total of 364 of these needless tragedies.  This study shows that these incidents can occur on days with relatively mild (i.e., ~ 70 degrees F) temperatures and vehicles can occur reach life-threatening temperatures very rapidly. 

STATISTICS

  • Total number of U.S. hyperthermia deaths of children left in cars, 2008:  4
  • Total number of U.S. hyperthermia deaths of children left in cars, 2007:  35
  • Total number of U.S. hyperthermia deaths of children left in cars, 1998-2007:  365
  • Average number of U.S. child hyperthermia fatalities per year since 1998: 36
 

 

  • Airbags vs. Hyperthermia Deaths

    • In the three-year period of 1990-1992, before airbags became popular, there were only 11 known deaths of children from hyperthermia.

    • In the most recent three-year period of 2004-2006, when almost all young children are now placed in back seats instead of front seats, there have been at least 110 known fatalities from hyperthermia...a ten-fold increase from the rate of the early 1990s. (graphic) [Important note: This in no way implies that it is advocated that children be placed in the front seat or that airbags be disabled.]

     

  • Circumstances

    • An examination of media reports about the 361 child vehicular hyperthermia deaths for a ten year period (1998 through 2007) shows the following circumstances:

      • 51% - child "forgotten" by caregiver

      • 30% - child playing in unattended vehicle

      • 18% - child intentionally left in vehicle by adult

      • 1% - circumstances unknown

 

  • Ages

    Children that have died from vehicular hyperthermia in the United States (1998-2007) have ranged in age from 7 weeks to 13 years.  The average age is approximately 24 months.  Below are the percentage of deaths (and the number of deaths) sorted by age.
    • Less than 1 year old = 33% (113)

    • 1-year old = 22% (77)

    • 2-years old = 21% (75)

    • 3-years old = 12% (43)

    • 4-years old = 5% (18)

    • 5-years old = 3% (10)

    • 6-years old = 2% (6)

    • 7-years old = 1% (2)

    • 8-years old = 1% (2)

    • 9-years old = 1% (2)

    • 10-years old = 1% (3)

    • 11-years old = 0% (0)

    • 12-years old = < 1% (1)

    • 13-years old = < 1% (1)

    •  Unknown = 1% (2) 

click to enlarge images and for more details
 

2008 Fatalities

2007 Fatalities

2006 Fatalities

 


2005 Fatalities


2004 Fatalities

2003 Fatalities


1998-2007 Fatalities

1998-2007 Child Hyperthermia
Fatalities by State

 
1998-2007 Child Hyperthermia
Per Capita Fatalities by State
 

click to enlarge images and for more details

LEGAL

  • Only 12 states have laws prohibiting leaving a child unattended in a vehicle.
  • Currently 15 states have proposed legislation making it a crime to leave a child unattended in a car, van, truck or SUV.
  • In two states it is only a crime if the child is injured or dies (Kentucky, Missouri)
  • The remaining 24 states do not have laws specifically against leaving a child unattended in a vehicle
  • An Associated Press (AP) study "Wide disparity exists in sentences for leaving kids to die in hot cars" examined both the frequency of prosecutions and length of sentences in hyperthermia deaths
    -  Charges were files in 49% of all the deaths.  81% resulted in convictions.
    -  In cases with paid caregivers (i.e., childcare workers, babysitters) 84% were charged and 96% convicted
    -  Only 7% of the cases involved drugs or alcohol
 
 States with "Unattended Child" Laws

MEDICAL

  • Heatstroke occurs when a person's temperature exceeds 104 degrees F and their thermoregulatory mechanism is  overwhelmed
    -  Symptoms include :  dizziness, disorientation, agitation, confusion, sluggishness, seizure, hot dry skin that is flushed but not sweaty, loss of consciousness, rapid heart beat, hallucinations
  • A core body temperature of 107 degrees F is considered lethal as cells are damaged and internal organs shut down 
  • Children's thermoregulatory systems are not as efficient as an adult's and their bodies warm at a rate 3 to 5 times faster than an adult’s.

VEHICLE HEATING DYNAMICS

The atmosphere and windows are relatively “transparent” to the sun’s shortwave radiation (yellow in figure below) and are warmed little.  The shortwave energy does however warm objects that it strikes.  A dark dashboard or seat can easily reach temperatures in excess of 180 degrees F.

These objects (e.g., dashboard, steering wheel, childseat) heat the adjacent air by conduction and convection and also give off longwave radiation (red) which is very efficient at warming the air trapped inside a vehicle.

 

Objects Heated by the Sun Warm Vehicle's Air


CLICK HERE FOR ANIMATION (~700K)
( Hi-Res ~ 2.5 mb.WMV file)
Individual Frames:
0 min, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min
(Courtesy of General Motors)

VEHICLE HEAT STUDY

  • Study of temperature rise in enclosed cars on 16 dates between May 16 and Aug. 8, 2002.
  • Ambient temperature were between 72 and 96 degrees F.
  • Dark Blue mid-side sedan with medium grey interior
  • Also tested with windows “cracked”

click to enlarge images

All 16 Cases

Average Temperature Rise

SAFETY RECOMMENDATIONS

  • NEVER LEAVE A CHILD UNATTENDED IN A VEHICLE.  NOT EVEN FOR A MINUTE !
  • Be sure that all occupants leave the vehicle when unloading. Don't overlook sleeping babies.
  • Always lock your car and ensure children do not have access to keys or remote entry devices.  If a child is missing, check the car first, including the trunk. Teach your children that vehicles are never to be used as a play area.
  • Keep a stuffed animal in the carseat and when the child is put in the seat place the animal in the front with the driver.
  • Or place your purse or briefcase in the back seat as a reminder that you have your child in the car.
  • Make "look before you leave" a routine whenever you get out of the car.
  • Have a plan that your childcare provider will call you if your child does not show up for school.

CONCLUSIONS

  • Average elapsed time and temperature rise
    • 10 minutes ~ 19 deg F
    • 20 minutes ~ 29 deg F
    • 30 minutes ~ 34 deg F
    • 60 minutes ~ 43 deg F
    • 1 to 2 hours ~ 45-50 deg F
  • “Cracking” the windows had little effect
  • Vehicle interior color probably biggest factor
  • "Parents and caregivers need to be educated that a vehicle is not a babysitter or play area ... but it can easily become an oven"

CONTACT INFORMATION

Jan Null, CCM
Adjunct Professor of Meteorology
San Francisco State University
Phone: (408) 379-7500
Email:
jnull@ggweather.com

RESOURCES  & LINKS


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WWW http://ggweather.com