The National Weather Service is partnering with the National Highway Traffic Safety Administration and Safe Kids Worldwide to raise awareness about the dangers of leaving kids in cars. As of July 10, 2013, 19 children nationwide have lost their lives due to heat because they were left inside a vehicle this year. This is absolutely preventable if people are simply aware of the problem.
Never Leave Children, Disabled Adults or Pets in Parked Vehicles
Each year, dozens of children and untold numbers of pets left in parked vehicles die from hyperthermia. Hyperthermia is an acute condition that occurs when the body absorbs more heat than it can handle. Hyperthermia can occur even on a mild day. Studies have shown that the temperature inside a parked vehicle can rapidly rise to a dangerous level for children, pets and even adults. Leaving the windows slightly open does not significantly decrease the heating rate. The effects can be more severe on children because their bodies warm at a faster rate than adults.
Courtesy of San Francisco State University. Use of this graph does not imply NWS endorsement of services provided by San Francisco State University.
The sun's shortwave radiation (yellow in figure below) heats objects that it strikes. For example, a dark dashboard or seat can easily reach temperatures in the range of 180 to over 200°F. These objects (e.g., dashboard, steering wheel, child seat) heat the adjacent air by conduction and convection and also give off longwave radiation (red in figure below) which is very efficient at warming the air trapped inside a vehicle.
Shown below are time lapse photos of thermometer readings in a car over a period of less than an hour. As the animation shows, in just over 2 minutes the car went from a safe temperature to an unsafe temperature of 94.3°F. This demonstration shows just how quickly a vehicle can become a death trap for a child.
Objects Heated by the Sun Warm Vehicle's Air
CLICK HERE FOR ANIMATION (700K)
( Hi-Res ~ 2.5 mb.WMV file)
0 min, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min
Animation Courtesy of General Motors and San Francisco State University. Use of this animation does not imply NWS endorsement of services provided by General Motors and San Francisco State University.
Hyperthermia deaths aren't confined to summer months. They also happen during the spring and fall. Below are some examples.
The atmosphere and the windows of a car are relatively transparent to the sun’s shortwave radiation yellow in figure below) and are warmed little. This shortwave energy, however, does heat objects it strikes. For example, a dark dashboard or seat can easily reach temperatures in the range of 180°F to more than 200°F. These objects, e.g., dashboard, steering wheel, childseat, heat the adjacent air by conduction and convection and give off longwave radiation (infrared), which efficiently warms the air trapped inside a vehicle. Learn more about excessive heat and cars.