Dry ice is NOT a good way to cool your car's interior during an Arizona summer.

Dear Car Talk

Dear Car Talk | Jan 01, 1998

Dear Tom and Ray:

I live in Phoenix, where the temperature runs as high as 120 degrees in the
summer. Inside the car, the temperature is much higher. And even though I have
air conditioning, it is unbearably hot when first getting into the car and for
the first 10 minutes. I am so desperate to find a way to cool down the car's
interior, that I have tried putting frozen milk jugs in the back seat in hopes
of dropping the temperature a few degrees. I was wondering if it would work to
put a big box of dry ice in the back seat when I first get in. Does dry ice
give off any toxic fumes? -- Patricia

TOM: Yes. Dry ice DOES give off potentially toxic levels of carbon dioxide. And
Jim Davis, head of the Car Talk Chemistry Labs, says that while it's not as
poisonous as carbon MONoxide (the stuff we normally associate with tailpipes),
carbon DIoxide is toxic when it is more than a few percent of the air we

RAY: And in a closed car, it could very quickly cause symptoms ranging from
nausea, to breathing difficulties, to death. Note: Jim says "death" is not
recommended (forgive his pedagogical side ... he's a Harvard Chemist in his
spare time).

TOM: Dry ice is also not a very practical solution, Patricia. First of all,
you've got to get some -- most Amana Side by Sides weren't coming with dry-ice
makers last time I checked. Then you have to schlep the stuff to the car with a
pair of ice tongs everytime you want to drive somewhere.

RAY: So let's take a look at some more practical solutions to your problem,
Patricia. One is to simply leave the windows open -- or partially open. Since
it's so hot and dry where you live, you don't have to worry about rain. And if
security isn't a big concern for you, this is a quick and simple fix.

TOM: And there are others. One is to park in the shade (a long-lost art).
Another is to use a sun shade, which covers the inside of your windshield and
keeps the car from heating up as much in the first place. Note: Jim says
"remember to remove shade before driving away."

RAY: If those solutions don't dissipate enough heat, you can buy one of those
little solar-powered fans that fit inside the window. You put this thing in the
window, then roll up the window right below it (so there's no security risk),
and then the fan exhausts hot air from the car while you're inside shopping at
Sigmund's Cigar Emporium.

TOM: You can probably find one of these fans at the larger auto parts stores or
through the J.C. Whitney mail-order catalog. Good luck, Patricia.

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