Use the A.C. Even on cool days. And set the air conditioner's air flow switch to "recirculation." This combination minimizes the external pollen and dust that comes into the car.

At Work

Numerous chemicals and odors in office buildings can trigger allergy or asthma attacks, particularly given today's sealed-tight office environments. Additionally, some office equipment, such as photocopiers, computers, fax machines, and printers, give off ozone and other irritants that can exacerbate asthma.

The Occupational Safety & Health Administration estimates that 11 million workers are exposed to some 200 substances associated with occupational asthma, and about 15 percent of "disabling" cases of asthma are related to the workplace. If you fall into this category, you have two options: change jobs or change your environment. To create a healthier work environment, make the following moves:

Treat your work space like your home. Identify the most likely sources of allergens and irritants, and make as many improvements as your boss will allow.

Keep your space clean. Piles of paper, books, tools, and product samples cause two problems. First, they attract dust and allergens; second, they prevent the cleaning staff from doing their jobs thoroughly.

Clear away food and drink. Old cups of coffee, bagel crumbs on the floor, a half-eaten sandwich left overnight on your desk all contribute to dirt, mold, and a generally unhealthy atmosphere.