I get so irritated when I hear someone say, "I think I'm getting sick" because I know, inevitably, in a day or two, they will be sick*. When I think to myself, "Oh no, I think I'm getting a cold" I immediately begin drinking a lot of fluids, get more sleep, and basically think myself healthy. I am not a granola-crunching nutjob, but I really believe in mind over matter. 9 times out of 10, if you're feeling under the weather, its your body's way of telling you to slow down or up the nutrition.
So slow down and up the nutrition! And don't get sick! Quit calling out of work and bailing on friends! Stop missing out on life because you're laying in bed!
+Title courtesy of Queens Of The Stone Age
*I also don't think people should say they're sick unless they have a sore throat, a fever, or are vomiting. Otherwise, it's a cold.