If your baby has a cold with no complications, it should resolve within 10 to 14 days. Most colds are simply a nuisance. But it's important to take your baby's signs and symptoms seriously. Even though the local drug store may sell infant cold medicine, it is not for infants under 6 months! Never take a chance and give it to your baby because it can actually complicate things. Normally, the only thing a doctor will allow you to give your infant is infant Tylenol (acetaminophen). If symptoms don't improve or if they worsen, it's time to talk to your doctor.