When a young baby is congested due to a cold, sleeping can be a challenge. But there are things you can do to improve their sleep. First, try using a cool-mist humidifier in their room. Not only is the moist air comforting, but it also can keep mucus flowing and prevent it from clogging your baby's nose. Before bed, try using saline drops to thin the mucus and a nasal aspirator to clear away any excess mucus. If your baby wakes in the middle of the night to feed, you can clear their nasal passages again if they seem particularly stuffy.