Some colds are like mice, timid and annoying; others like dragons, accompanied by body aches and deep misery. In AH-CHOO , Jennifer Ackerman explains what, exactly, a cold is, how it works, and whether it's really possible to "fight one off." Scientists call this the Golden Age of the Common Cold because Americans suffer up to a billion colds each year, resulting in 40 million days of missed work and school and 100 million doctor visits. They've also learned over the past decade much more about what cold viruses are, what they do to the human body, and how symptoms can be addressed. In this...