Headache, fever, throat pain, and a dry cough are usually due to a viral infection, such as the flu, which often improves with rest and simple care. Drink plenty of warm fluids, do salt water gargles, take steam, and get good rest to help your body recover. You can take basic pain relief to reduce fever and discomfort, and eat light food. If symptoms become severe, last more than a few days, or you have breathing trouble, consult your doctor