SJ professor says vehicles can become a deadly oven in just minutes

The accidental death of an infant left in a hot car Tuesday is drawing new attention to this all-to-common tragedy. Even in the midst of a September cooling trend, the danger persists. Brilliant sun and a vehicle parked with windows up can become a deadly combination for a child left in the back.

“Within 10 minutes the temperature has risen 19 degrees above whatever the air temperature is,” said Professor Jan Null.

Null, a San Jose State meteorologist, started studying the science behind how quickly cars heat in 2001. This came after a South Bay child died after being exposed to high temperatures inside a closed car. 

Null outfitted a minivan with a thermometer and linked the gauge to his iPad. On a 69-degree day in Saratoga, the temperature inside is 112 degrees and rising. The vehicles closed windows, dark surfaces, and exposure to direct sunlight send the inside temp to about 45 degrees above the outside temp in just an hour.

“All these are radiating their heat and heating up the air in the car. And even cracking the windows [only] makes a two or three degree difference.”

Tuesday 18-month-old Lily Aracic died after a relative left the girl inside a car on Hardie Drive in Moraga. Investigators say it was 80 degrees outside. Using professor Null’s equation, it would have been about 125 degrees inside the car. The baby died to heat stroke.

“They performed every lifesaving measure that they could and transported the infant toJohn Muir Medical Center in Walnut Creek where she was pronounced deceased,” Moraga Police Chief John King said Wednesday.

So far this year in the Bay Area, there have been three deaths due to children left in hot cars. Nationally, there have been 46. Professor null says that’s nine ahead of the average, and there’s still warm days ahead in warm weather states such as Florida, Arizona, and California. He says there’s no explanation why this year is outpacing last, or why this type of tragedy continues to happen, despite all the warnings.

“If we had the answers to that, we’re looking at Nobel prizes, you know, trying to predict human behavior,” said Null, as he used a hand-held thermometer to check the temperature of the minivan’s seats.

Null and others hope continuing the message about the dangers sun and closed cars can produce to a child left unattended for only a few minutes will turn the tide.