Not just for when you have a cold, you can take them when you're well too! In fact, they're downright addictive, the more you have, the more you want and the less strong they taste.
After having many `friends, the menthol can cause interesting effects on one's taste and temperature perception. A nice deep breath of air feels like ice cold, arctic air. Chilled water tastes like it's liquid nitrogen, to the point where a normally refreshing cool glass of water is so cold it's painful to drink.
I found `friends to be a great cigarette substitute when I gave up smoking.
A `friend in need is a `friend indeed.