How long for a cold...?

mharts05

My 9 month old twins came down with a cold over a week ago. The fever is gone, they are playing and active, but they still have runny noses and a little cough. How long does it take for these things to go away? We went to the doctor but he said it just had to run its course but I still worry. Also, how long do you keep them in a steamy bathroom to help with the congestion?