One of the reasons we get more viruses in fall and winter is because the air is drier. A lack of humidity allows viruses to thrive and makes it harder for our nasal passages to trap and eliminate them. So keep a humidifier going at home. But make sure to keep it clean. Put about 5 drops of oregano, eucalyptus or peppermint oil in the water reservoir. The oil will reduce germs and make the air smell nice. However, you’ll still need to clean the reservoir weekly.