Fever (higher than 100ø F) A fever occurs when your body temperature increases in response to illness or injury. Your temperature is considered elevated when it is higher than 100øF.Chills
Body chills that are not related to a cold environment can be a sign of the flu.
Headache
A headache associated with the flu may appear suddenly, and be related to body aches or nasal congestion you’re experiencing.
Extreme tiredness
It’s normal to feel tired at the end of a long day or when you don’t get adequate sleep, but unexplained tiredness can be a sign of the flu.
Dry cough
Know your cough. A productive cough (coughing up mucus) is common with a cold, while a nonproductive or dry cough (with no mucus) is associated with the flu.
Sore throat
Swelling in the throat can lead to a sore throat.