Turn your car's heated window on.This last-resort method is appropriate when you don't have a lukewarm water, de-icing fluid, or any conventional scraping tools at your disposal - for instance, if your car's window froze in the car park whilst you were at work. Because you're going to attempt to remove the ice with a credit card or other improvised tool, it's wise to give yourself as much help as possible. To begin, start your car and turn on your heater/defroster up as high as it goes. Leave this running throughout the process - over time, it will soften and begin to melt the ice, making your job much easier.

Find an appropriate credit card. Dig through your wallet to find a credit card or any similar stiff, solid plastic card. Don't use a laminated card - these aren't stiff or sturdy enough to scrape the ice effectively. If possible, try to use a card that isn't important to you, like an old, expired credit card, as this method carries the risk of damage to your card. However, don't keep it for too long, as your card provider would recommend that you destroy your old card as soon as possible for counter-fraud purposes.

Start scraping. Hold the long edge of your card at an angle against the window and push firmly. Try to keep the card as straight as possible, not allowing it to bend or flex as you scrape. If you do, you may end up deforming or breaking it.

• Be persistent! As far as scrapers go, credit cards can require more effort than dedicated scrapers. You may need to push quite hard to get results.
• If you're worried about breaking your card, you may want to double or triple the strength of your scraper by holding two or three cards stacked as you scrape.

Use your wipers and fluid to assist. As you scrape ice away, you'll probably accumulate ice shavings at the edges of the window. Periodically, spray wiper fluid and run the wipers for a few seconds. The wiper fluid can help soften up any remaining ice, while the wipers themselves will help brush the ice shavings out of the way. Between the scraping action of your credit card, your wipers and fluid, and your defroster, your window should be free of ice within a few minutes.

Place rice in a mitten or heavy duty zip-lock bag and microwave for 30 seconds to a minute. You may need to make several of these to complete the job.

Pass the rice packet back and forth over the inside of the window while seated inside your car. This will warm the glass and the ice will melt.

• Sodium acetate hand-warmers also can be used in this manner and can stay ready in the car. A quick click activates the heat reaction, then you can recharge the warmers by boiling in water.
• The advantage of this method over scraping, is because the glass is warmed as you start to drive it will not re-frost. Also you stay warm and dry inside the car while prepping for departure.

Be careful and quick. Just like boiling water may crack glass, holding a hot warmer in one place too long may stress the glass. Only allow it to remain in place long enough to start to show melting, as it will continue to melt while moving on to a new area. Windshield wipers and rolling down the side windows can be used to clear moisture.

Cover your windows at night. One sure-fire way to ensure you're not delayed by icy windows in the morning is to prevent ice from forming in the first place. To do so, cover your windows with a towel, a folded sheet, or a piece of cardboard at night before dew or ice forms on the window. Try to arrange the cover tight against the window so that dew (and eventually, ice) can't form in any loose spots.

• One useful trick for your front windshield is to use your car's windshield wipers to hold your cover in place. For your other windows, you may want to use small rocks or other weights to pin your cover down.

In the morning, remove the window covers. Pull your towels, sheets, etc. away from the window. They may be damp and/or icy, so, if you plan to use your window covers again at your destination, be sure to lay down a water-tight barrier, like a tarp, before throwing them in your trunk.