To investigate the matter, researchers studied how long it takes different types of cars to heat up on hot days. The findings were sobering: Within 1 hour, the temperature inside of a car parked in the sun on a day that reached 95 degrees Fahrenheit (35 degrees Celsius) or hotter, hit an average of 116 degrees F (47 degrees C).

The cars’ dashboards got even hotter, reaching 157 degrees F (69 degrees C), on average; the steering wheels climbed to a temperature of 127 degrees F (53 degrees C), on average; and the temperature of the seats hit 123 degrees F (51 degrees C), on average.