How do you treat a newborn with a cold and no fever?

More likely irritant: Nasal congestion at that age is most often due to exposure to fragrance, dust, smoke or other odors.This often causes swelling inside the nose & mucous buildup. Saline nose wash used in liberal amounts will often clear this up.

See a doctor: Newborns aré very delicate and, up to around two months of age are at a higher risk of developing more serious infections. In general, no cold medications should be given to a newborn, only normal saline nose drops, to help clear and humidify secretions. Your baby's doctor should examine him and determine the right treatment and if tests need to be done.