Baby has a chest/throat cold, coughin?

A nasty chest/throat cold has been going around, its one of those ones that hurts your throat and makes you cough and your throat sound real gruff and ucky. My 9 month old son had a runny nose for several days now, and my husband and i both got the cough part already. He has started coughing and his throat sounds awful, and it is too late to call a doctor. What can I do for him to make him feel better? So far I am trying a warm bath, chicken broth, those vicks plug-in vaporizer things, and lots of cuddles. What else can I do to make him feel better?