According to Some Doctor With a Web Page:
Classically, the flu begins abruptly, with a fever in the 102 to 106 degree range (with adults on the lower end of the spectrum), a flushed face, body aches, and marked lack of energy. Some people have other systemic symptoms such as dizziness or vomiting. The fever usually lasts for a day or two, but can last five days.
Somewhere between day 2 and day 4 of the illness, the "whole body" symptoms begin to subside, and respiratory symptoms begin to increase. The virus can settle anywhere in the respiratory tract, producing symptoms of a cold, croup, sore throat, bronchiolitis, ear infection, and/or pneumonia.
The most prominent of the respiratory symptoms is usually a dry, hacking cough. Most people also develop a sore (red) throat and a headache. Nasal discharge and sneezing are not uncommon. These symptoms (except the cough) usually disappear within 4 to 7 days. Sometimes there is a second wave of fever at this time. The cough and tiredness usually lasts for weeks after the rest of the illness is over.