Insider Blog: Effectiveness of car windshield sun shades

Sweltering summer temperatures quickly become dangerous in cars under the sunshine. Some may try to combat this by cracking windows, leaving the sunroof open, or putting a sun shade on the windshield. Most tricks do not stop a car from quickly heating up but others can help. Never rely on any of these measures to attempt to leave someone in the car; never leave children or pets unattended in a hot car.

The inside of a car heats up just as fast whether the windows are cracked or left closed. On a 90-degree day, the interior of a car can reach over 130 degrees in just an hour. And an open sunroof is typically too risky due to possible theft or unwanted bird droppings in your car.

Windshield sun shades though have been shown to reduce interior car temperatures by up to 40 degrees. This can help keep dashboard and seat temperatures lower and safer to touch. The color of the sun shade is also important. Shiny reflective shades and darker shades can potentially focus intense heat on your windshield and expand cracks in the most extreme heat. The best bet is a neutral light-colored shade that is not reflective. Be sure you get the right fit of sun shades for the size of your windshield.