Apply few drops of eucalyptus oil mixed with a carrier oil on your scalp.2 drops in 10 ml.
Hmmm, I didn't know that one...
I know that eucalyptus globulus is usually used to stimulate your appetite and to relieve a cold that is heavy/located in your nose (don't know how to express it otherwise) with warm water and inhalation.
By "scalp", do you mean the forehead, face or directly on your scalp and hair?
When the cold is located in your neck and throat, it seems better to apply it to your torso/abdomen and throat I think.