Nasal congestion is very common in kids. It can be cause by various factors like weather condition and sometime it can even be hereditary. In my native place mothers use to apply a lotion made out of garlic fried with mustard oil. The oil is applied on the chest of the kids and back as well.
This is very effective as it is thought to improve the air circulation system in the body besides controlling the body temperature. In addition to this method, I think the following tips from this video will help you in treating nasal congestion in your kids. Happy breathing!
How to Relieve Nasal Congestion in Infants — powered by ehow
Mothersforum.org suggests you consult your doctor before taking serious steps towards childcare as every child is unique.