Winter can reach bitterly cold temperatures here in McHenry County. With wind chills, winter carries potentially fatal consequences across the barren landscape. Traveling on such days is a challenge – a challenge to safe and warm even in your car. But, when you turn on the heat in your car the heated air pours out of the vents and warms you to the bone, right?

It all depends on whether your car’s heater works. The heat in the inside of the car is provided, ironically enough, by the car’s cooling system. We call the fluid inside that system coolant in the summer and anti-freeze in the winter. But, whatever season, it still fulfills a crucial role in an automobile.

Coolant keeps the engine from overheating. Even in the coldest weather, without adequate coolant, your car will quickly overheat. On the other hand, in the winter, when the car isn’t running, the anti-freeze has the capacity to remain in a liquid, non-frozen state even when temperatures are terribly cold.

When the cooling system is working properly, the coolant/anti-freeze runs back and forth between the engine and the radiator. In the radiator, air passes by the coils and fins carrying the heat away. The heat is then dispersed out the bottom of the engine compartment to fall behind you as you drive.

The cooling system, however, makes one detour between the radiator and the engine; it also runs to the heater core behind the dashboard. The heater core is, essentially, a small radiator also made of coils and metal fins. When you turn the fan on inside the car, it draws air through the heater coil. Heat moving from warm to cool areas, the heat is transferred from the heater coil to the passing air.

On the one hand, the heater coil plays an important role by providing a reasonable temperature inside the car. On the other hand, it plays a vital role in terms of defrosting the windshield. With the prior, it’s the difference between a bitter-cold drive and a ride in comfort. With the latter, it’s the difference between a blocked, unsafe view through a frosted windshield and a clear view.

If you haven’t had your cooling system checked, this is a good time to do so. While they’re at it, you can have your trusted auto repair technician check the heating system inside the car. They can make sure the heating coil isn’t clogged or leaking. They can also check to make sure your heater is working at its maximum potential.