Potatoes, Spanish rice, brownies and cake, all slowly cooked in cars parked under the searing Tucson sun — all to make an important point.

During the heat of a Tucson summer, cars can become ovens, so don't leave children and pets in them unattended, said Vicki Gau-beca, the public affairs director for the UA's Zuckerman College of Public Health.

Gaubeca was explaining the reason the college's faculty and staff had stuffed the dishes into several cars near University Medical Center Wednesday morning.

"It's a fun, lighthearted way to highlight an important public safety issue," she said.

They pulled the dishes out of the cars about 4 p.m. to see how much the food had cooked.

Those dishes included rice pudding, cornbread, even an omelet, which got a little firm but didn't get hot enough to make it safe to eat. They also tried popcorn to see whether the car would warm up enough to explode the little yellow kernels. It didn't.

But it was hot enough to cook the brownies and the rice. A cooking thermometer plunged into the Spanish rice read 170 degrees after the baking dish was pulled from a car.

Capt. Paul McDonough, a Tucson Police Department spokesman, agreed that leaving those most vulnerable — the very young, the elderly and family pets — in an unattended vehicle can have fatal results.

A general rule of thumb is to consider it 20 degrees hotter in a vehicle than the outside temperature, McDonough said. "If you get out of the vehicle, the child comes with you," McDonough said.

An administrative associate at the college, Nancy Casady, came up with the idea for the car cookout after she realized she could bake cookies in her parked vehicle.

She talked with some other faculty members and staffers who agreed it would be a good way to get people's attention about just how hot it can get inside a parked car.

After checking on some of the desserts during the day, Casady said many of the treats appeared to be cooked within four hours of having been locked in the car.

That shows it quickly gets hot enough to cook inside a vehicle, Casady said, and for her it sends a pretty clear message: "Don't leave anything in your car that you wouldn't leave in your oven," she said.