Anyone who's plunked a few ice cubes into a beverage has witnessed the effect of thermal shock. The ice will crack, sometimes so violently that the cube will split into smaller pieces.

This effect is a result of differential expansion. The core of the ice cube remains cold while the surface, exposed to the warmer liquid, expands. The difference in forces puts enough pressure on the ice to crack it.

Differential expansion is also one reason why you need to be more aware of your windshield's condition during the winter. Gerber Collision & Glass, a Chicago-based business, says your windshield will be under different stresses on cold days. Heating up the interior of your vehicle will cause the glass to expand, while the surface exposed to the chilly atmosphere will contract.

Windshields are designed to withstand the forces resulting from the different temperatures. Glass America, an auto glass service chain, says cold days alone aren't enough to damage the windshield. However, low temperatures can worsen existing chips and cracks.

When there is a chip or crack in the windshield, moisture can drip into it. During cold temperatures, this water will freeze and expand. This process puts additional stress on the glass, causing cracks to spread.

Since the windshield will be weakened by chips and cracks, it will be less capable of withstanding differential expansion. The vehicle's warm interior and the cold outside temperatures will still put competing forces on the glass. Even the normal process of putting on the defroster or heater can gradually cause windshield damage to get worse.

A number of circumstances can cause windshield damage, including pebbles kicked up by other vehicles on the road. During the winter, a driver may inadvertently damage their own windshield through careless behavior.

Scraping ice off the windshield is a common task during the winter. It can also be a very frustrating one. Secured Auto Glass, a Nevada company, says people can accidentally chip the glass if they stab at the ice with the sharp edge of a scraper.

Drivers who are running late may make the disastrous mistake of pouring hot water over the ice on the windshield. The sudden change in temperature will cause the glass to expand quickly, and the stress can easily cause cracks to form.

If the ice on the windshield is proving particularly troublesome, you can start the engine to take advantage of the heating system. The engine will warm up gradually, so turning on the defroster will warm the windshield slowly enough that it will not cause damage. This process will eventually weaken the hold of the ice on the windshield, making it easier to scrape off.

Chips and cracks in the windshield can be troublesome even if they are small. Everyday pressures on the car, such as bumps in the road, will cause the cracks to spread. Action Auto Glass, an Oregon company, says the sun creates a distracting glare when it hits this damage. Water can also leak into the vehicle during rain or snow.

If you notice a chip or crack in your windshield, get it repaired as soon as possible. Taking this action before the damage gets too widespread will allow you to repair it without replacing your windshield, and it can also improve the structural integrity of your vehicle.