A head cold, or common cold, is a viral infection of the nose and throat. It is usually a mild illness, and involves symptoms in the head, such as a stuffed, runny nose and watery eyes.

Viral infections are illnesses caused by a virus rather than bacteria or fungi. Many viral infections can cause skin rashes, called exanthems. Most clear up on their own, but some require medication.

It’s generally believed that warm liquids work better than cold ones to ease symptoms of the flu, and some scientific evidence backs up that conventional wisdom. In one of the most recent ...