The fastest and safest way to defrost your windshield is to start your car, turn on the defroster to warm, and activate the A/C compressor. While it warms up, manually scrape off the bulk of the ice. The key is using the car's HVAC system correctly: the warm air melts the thin layer of frost the scraper can't get, while the A/C dehumidifies the air to prevent interior fogging. Relying solely on the car's heater wastes time and fuel.
First, clear any snow from the car, including the roof. Start the engine and enable the defrost setting (the windshield icon). Set the temperature to high and the fan to its highest setting. Crucially, press the A/C button to turn it on. Even though you're heating the car, the A/C compressor removes moisture from the air, which is essential for clearing the inside of the windshield quickly. Turn on the rear defroster (the zigzag lines icon) if you have one.
While the system warms up—which can take a few minutes—get out with a plastic ice scraper and brush. Use the brush for snow and the scraper for ice, pushing it in single, firm strokes. Never use hot water, as the extreme temperature change can cause the glass to crack. Also, avoid using the windshield wipers to clear ice, as this can damage the wiper blades and their motors. For a light frost, a commercial de-icing spray can be effective, but the scraper-and-heater method is most reliable. The entire process should take about 5-10 minutes for a thoroughly cleared view.
