Eucalyptus is known for its ability to soothe colds and flues. It is  incorporated in many medicinal and health products that aid in clearing nasal passages, and sooth bronchial tubes when clogged. 
 
A cup of hot eucalyptus tea, contains, eucalyptol, the source of its spicy-yet-cooling flavor. It also contains a number of other ingredients, including flavonoids, quercetin, and tannins which act as antioxidants, making eucalyptus tea a natural source of antioxidants.