Now, it is obvious that you will not be able to get your windshield fixed the moment it cracks. But there are a few things which you can do to prevent the crack from getting bigger in the meantime. Even something as simple as temperature changes can cause the crack to widen. So don't wash your car using hot water or cold water when the weather is cold or hot. This may even make the crack spider which will make fixing it impossible. Unwanted particles may enter the crack as well and once they do this it is very difficult to clean them.​