When your car has been in the sun, it can get quite hot. To cool it down as quickly as possible, quickly air the door several times. Get in the car and, when you start driving, turn the air conditioning on to the highest setting. Roll the windows down for a few seconds and then roll them up as the car cools down.
Steps
Method 1 of 2: Ventilate the door and use the air conditioner

Step 1. Open a window and a door
Roll down the passenger side window. Next, stand outside the car and open the driver's side door using the door handle. With the window down, you're ready to create a low-pressure area that blows hot air out and draws cool air in.

Step 2. Vent the door
Quickly push the door toward the car, stopping just short of closing it. Repeat this six to eight times, and then get in the car.

Step 3. Start the car
Since air conditioning requires air to move over the condenser, using the air conditioner while you are stationary will not cool the car very quickly. A little driving will prepare you to cool down the car as quickly as possible.

Step 4. Turn on the air conditioner while driving
Set the temperature to the coldest setting and the fan speed to the highest setting.
- Use the fresh air setting (as opposed to the recirculation air setting), until the indoor air temperature drops below the outdoor temperature, and then switch to recirculation.
- When you first turn on the air conditioning in a hot car, you will likely feel a blast of hot air. After a few minutes, the temperature will start to drop.

Step 5. Roll down the windows
Keep the windows down for a minute or two to get the initial hot air out of the air conditioner and to circulate the air. Once the air conditioning has cooled the car to a comfortable point, roll up the windows and keep them up.
Method 2 of 2: Keep the car from heating up

Step 1. Park in the shade
If possible, always park under a tree, in the shade of a house, or in another cool place. If you park in a parking building, try to avoid the upper level (which is not protected by a roof).

Step 2. Invest in a parasol
Sunshades are folding windshield covers. To use the sunshade, press it against the inside of the windshield. Open the visors to secure the sunshade in place.
- The best sun visors will be coated in reflective chrome to deflect the sun's rays away from the vehicle.
- Some sun visors have small suction cups in the corners to allow them to better adhere to the windshield. This type can also be used on door windows.
- Put them in any window that is facing the sun (you may want to park with the front of the car facing the sun, to use a sunshade there).
- More than one can be used, but not on the door you need to open to get out of the car.
- Lower the visors to better hold the front sun visor in place and to reflect any light that passes through the top.
- Be careful that the sun visors can easily fly into the driver's face or out of the window once the car is moved, with the windows down. Fold them and place a heavy object on top, like shoes, or hold them in your lap to avoid it.

Step 3. Open a slit in the windows
Opening a slit in the windows can allow air to continue to move through the car, thus preventing the car from getting much hotter than the outside temperature.
- The bigger the slit in the windows, the better (an inch or two and a half centimeters each), especially if you can create a cross draft.
- Don't crack the windows if it's going to rain.
- One risk is that a burglar could reach your door locks using a hanger or other tool, so be careful of this.

Step 4. Use a seat cover
If you have dark brown or black seats, the car will absorb more heat than a car with bright or light colored seats. To remedy this, invest in some white or light-colored seat covers.