Does hot lemon and ginger cola really help with cold and flu symptoms?

Hot lemon and ginger cola is a uniquely Hong Kong drink. A few slices of ginger are heated in cola until boiling, then the mixture is poured into a glass and topped with a few fresh lemon slices. While some older-style restaurants or traditional Hong Kong-style cha chaan teng cafes still serve it, it is usually an off-menu item, known only to older Hongkongers. The drink is widely believed to help cure colds and flu. But does it really? The TCM perspective Ginger is a warming rhizome and a...