Runing noses in cold winters? Every one of us might havdd experienced the cold winter night and the running nose due to cold.have you ever thought why does it happen?in winters,the air arround us is cold but the lungs require a typical warm air for its functioning.so there will be an increased blood flow out to the nose,which keeps air intake warm.but it has a side effect,l.e.,the production of a high amount of snot from the muscus secreated by the glands in the nose.this is why the nose oftenly runs in winter.