When you were a kid, your mom and dad may have passed on this bit of wintertime wisdom:" If your toes are cold, put on a hat." Of course, they were right. The head accounts for up to 70 percent of the body's total heat loss.

Like the human body, your car has particularly cold-sensitive spots that demand protection when the temperature drops. Pay special attention to the following areas:

1. Tires. "When it comes to driving on changing road conditions, ranging from dry, wet, icy and snowy, an important factor to consider is the tires," says Bob Toth of Goodyear. "It doesn't matter if it's a front-, rear- or four-wheel-drive vehicle. It will perform better if it has good tires."

But, says Toth, even the best all-season radials or snow tires won't give you the performance you expect without enough air. He notes that most tires lose about a pound of pressure for every 10-degree drop in temperature. On an underinflated tire, the tread face cups upward, away from the road surface. That leaves a huge void precisely where the tread should make the most contact with the road. The colder the weather, The more frequently you need to check the inflation pressure on all four tires.

2. Battery. How cold-sensitive is your battery? Ask the folks at the Battery Council International, the trade group that represents automotive battery manufacturers. They'll tell you a fully charged battery has 100 percent of its starting power at 80 degrees. But at 32 degrees, the juice available from the same battery drops by one-third. And at zero degrees, a fully charged battery delivers only 40 percent of the power it could deliver at 80 degrees. Can you squeeze enough juice out of your battery to get going on a frosty morning? Only a load test can tell you for sure. Any good repair shop can do it in less than five minutes.

3. Radiator. According to the marketing mavens at Prestone, who worry about such things, 37 percent of vehicle owners top off their radiators with either plain water or undiluted antifreeze/coolant straight out of the jug. If you count yourself among them, then you deserve an "A" for effort but an "F" in chemistry.

Almost all antifreeze formulas provide maximum protection against freezing when mixed 50-50 with water. (You can buy the convenient, ready-to-use pre-diluted formulas, but then you're paying for a half-gallon of antifreeze and a half-gallon of water.) Contrary to what you might think, a higher concentration of antifreeze does not necessarily mean better protection. Adding straight antifreeze so that the concentration rises above 50-50 might actually make the mixture more likely to freeze.

Antifreeze should protect the cooling system down to 34 degrees below zero. To see whether yours does, have it checked by a technician using a hydrometer (which measures the fluid's specific gravity) or a refractometer (which measures light refraction). Either test is fast, and most shops will do it for free while you have other work done.

4. Windshield Washer Fluid. Fluid concentration matters not only with antifreeze but with windshield washer fluid as well. Nowadays, the proliferation of products has made a once-simple choice more exacting. You'll find many different washer fluid formulas, some of which offer no freeze-up protection at all. Take care to choose a winter formula containing methanol (wood alcohol) or some other anti-icing agent. Although the label won't specify the exact concentration, it will tell you the freezing point. Look for products good to at least 20 degrees below zero.

And top off your washer fluid frequently during winter. Methanol evaporates readily in a hot engine compartment. As it does, the freezing point of the solution rises. By adding fresh fluid frequently, you'll keep the washer reservoir ice-free.

5. Wiper Blades. In the cold, the rubber on your wipers becomes hard and brittle. It tears and pits as it sweeps across jagged ice globules stuck to the glass. By scraping the windshield thoroughly, you give your wipers a smoother surface, help them last longer and improve visibility.

Consider a set of specially designed winter blades. "Winter blades have a rubber boot that keeps snow and ice from building up on the metal or plastic structure of the blade," explains Brian Fisher of Federal-Mogul, a worldwide wiper blade supplier. That allows the blade itself to sweep cleaner.

6. Serpentine Belt. The cold that turns the rubber in your wipers hard and brittle does the same to the rubber in your serpentine belt, making frayed and worn belts more likely to break in winter. Unless you have a vintage car, you probably have one wide, serpentine belt driving the water pump, alternator and other accessories. If it looks shiny or glazed along its edges on the smooth side, if you can see the fabric peeking through the rubber, or if the ribs on the underside seem cracked or chunked-out, then replace it.

7. Engine Oil. All of today's cars specify a multi-grade oil (5W-20,5W-30 or 10W-30, for instance).The first number takes on special significance in winter, because it indicates the oil's viscosity (thickness) below freezing. In fact, the "W" stands for "winter." The lower the number, the thinner the oil in cold weather. Follow the specifications in your owner's manual precisely. Substituting 10W-30 for a 5W-30, for instance, will translate to harder starting, poorer lubrication and slightly lower fuel economy.