This will work wonders.
Get some Vick's BabyRub (make sure it's the baby version) and rub some on the baby's FEET. Put a blanket sleeper (with the feet built in) or socks over both feet. The runny nose, coughing and congestion will disappear. It works just as good in the daytime as it does in the night time. A cool mist humidifier works great too, just make sure you don't add any medication to it, it can put a film/coating on the lungs when its breathed in. My 14-month-old recently had a cold. I used this method and he was back to normal in no time. I'm glad I read about it, because with all the baby medications not being recommended for colds, it was a lifesaver.
PS There is a reason it's put on the feet (reflexology), it will open up the airways. Also, you would never want to put Vick's of any kind on a baby's nose or under the nose. They tough their face too much and will rub it around all over in their eyes, etc.
This works for adults as well.