Drinking warm fluids helps to loosen the secretions in your sinuses so that your mucus flows more freely, making you feel better faster. Studies show that drinking warm fluids relieves cold symptoms such as a runny nose, cough, sneezing, sore throat, and fatigue.  Hot, non-caffeinated tea will do the trick. Stick with a herbal tea like chamomile or peppermint to rehydrate yourself. Adding some honey and lemon will soothe your throat and help the effects last a little longer. Chamomile is good for reducing stress and fatigue, while peppermint relieves nasal congestion. Japanese Benifuuki green tea may help reduce nasal congestion and allergic symptoms when drunk regularly. The traditional herbal tea “Throat Coat” has been shown to be much better at relieving sore throat pain than regular teas.  Hot broth is also a good choice when you have a cold. Drink vegetable or chicken broth in large quantities, but look for low-sodium broths to avoid consuming too much salt. Chicken soup can help soothe a sore throat and loosen mucus to ease congestion.  If you're a coffee lover, there's no need to avoid it. Drinking coffee has been shown to increase alertness among those with colds. Children should still avoid caffeine. Warm water, tea, and broth should be the main fluids you take in, as too much caffeine can dehydrate you. Avoid alcohol. It may make nasal congestion and swelling worse.

TL;DR in Vietnamese:
Uống nhiều nước ấm.