These days, we often treat our car like an extension of our home and office. We chat on the phone, check our e-mail, eat, even take naps. Since most cars are continually exposed to the elements, they can quickly become land mines when it comes to allergies and asthma. To keep yours as allergen-free as possible, follow this advice.

Sniff the air. If your car smells like dirty socks, you've probably got mold. Check the air-conditioning coil, the carpeting in the car and trunk, and that old blanket you threw in the backseat after watching your son's soccer game in the pouring rain.

Avoid air fresheners. The scent can exacerbate asthma.

Clean your car regularly. That means more than running it through the car wash. It means steam cleaning the carpeting and upholstery every couple of weeks (unless you have leather upholstery), regularly wiping down the interior with a damp cloth, and throwing out any trash daily.

Time your commute. If at all possible, avoid congested streets and rush-hour traffic that can emit high levels of fuel exhaust.

Keep the insides dry. Wet feet, spilled drinks, or a window left open throughout a rainy night can all be the catalyst for some serious mold. If your car's interior does get wet, do what you can to dry it quickly. Use towels to sop up the moisture, and a fan to evaporate the remaining dampness.

Eat elsewhere. A car full of crumbs, shriveled French fries, lettuce leaves from the burger, and apple cores in the ashtray is a car full of mold and bacteria.