To prevent moisture from forming on the inside of your windshield during cold days, what should you do before using the defroster?

To prevent moisture from forming on the inside of your windshield during cold days, turning the heater on high and allowing the engine to warm up is the most effective approach. When the heater is activated, warm, dry air is circulated throughout the vehicle, which helps to raise the interior temperature. By increasing the temperature inside the car, you effectively reduce the likelihood of condensation forming on the glass due to the temperature difference between the inside and outside.

Warm air holds more moisture than cold air, meaning it can help absorb and combat the condensation that might form on the windshield. This process is crucial, especially in a cold environment where warm, moist air from your breath can easily clash with the cold glass, leading to fogging.

Other methods, such as turning the defroster on immediately or using a towel, might provide temporary relief but won't address the root cause of the moisture build-up as effectively as allowing the heater to warm the air in the vehicle. Opening a window may lead to the introduction of cold air into the vehicle, which could actually exacerbate the fogging issue rather than resolve it.