http://bit.ly/1LovK6P. I am proud to have my article published and eager to help you all make the best decision you can about singing should you find yourself sick leading up to a performance!
A quick summary of tips:
Take care of yourself first in the hopes that you can ward off any illness. At the first sign of illness or if you have been around others who are sick, start going to bed early, take extra Vitamin C, drink more water and of course keep washing those hands!
The weeks leading up to the big performance demand more of us mentally, physically, and time-wise. We are stressed if we are going to remember it all and do it right! This causes our defenses to be down and more likely to catch that cold.
Take some extra time to take care of you physically (as seen above) and mentally. Allow yourself a break from it all, but make it smart. Do some yoga or read a good book and get extra sleep. Make it something that relaxes you, but rests your voice.
Also, more tips can be found in other articles on this blog: Sick but Singing....Fa la la la lah..... and Wintertime and Singing, A Double Edged Sword.