How to avoid colds

Most people catch a cold two to four times a year, usually in the cold winter months. The nose runs, the throat is sore and red and the head hurts. If it is a common cold, you usually get better within a week. However, the same symptoms also occur with flu-like infections and can sometimes only be combated by taking antibiotics.
Of course, the most sensible thing is to avoid catching a cold in the first place. How can I prevent getting a cold?
