What is the best way to warm windshield glass?

Question:

What is the best way to warm windshield glass prior to repairing?

Answer:

Several methods can be used including: A 12V cigarette lighter, the vehicle’s defroster, hair dryer, heat lamp, heat gun and moisture evaporator. All these methods work, so it is just a matter of choice. However, in cold conditions, running the vehicle’s defrosters or using a heat lamp have the advantage of being somewhat more consistent