Don't Fly With A Cold

The headline says it all. It's really very simple. Don't fly with a cold. Every pilot should learn this, most of us know it, but many have broken this dictum at least once. You have a little cold, but it's a great day to fly or you have to be somewhere, so off you go. Bubbles squeak in your ears and nose, so you equalize the pressure during the climb to altitude. You feel pretty good at altitude, but when it's time to descend - uh oh, you've got a problem. Your head feels like it's in a vise, and descending increases the pressure.
http://www.aopa.org/members/ftmag/article.cfm?article=1272