just get on with it really, unless it's the flu which then obviously you are bed ridden. I've had my fair share of chest infections/cold and pneumonia this year and now I've just caught another cold thats worryingly gone to my chest again, off I go to the doctors in the morning. My advice would be don't smoke because some colds can turn into chest infections and when the lungs are weakened by smoking it's not good. I've ended up with COPD and I quit smoking 10 years ago
Oh and take Vitamin C