Here's a cool tip I found at Real Simple.
Although it’s not the height of cold and flu season, warm weather viruses can be nasty. So keep your immune system healthy, by singing or playing an instrument.
Two separate studies have found that singing out loud and playing instruments like the drums, not only improve your mood, but they also increase the concentration of antibodies that protect from invading germs.
As if you needed another reason to sing in the shower.