Flu fever range: what to know

A thermometer gives a more useful picture than judging warmth by touch. Fever reflects the body's response to infection, while chills can happen as the body adjusts its temperature. Temperature can vary with the time of day, recent activity, fluids, and the method used to measure it. A fever pattern cannot confirm flu by itself; common cold, COVID-19, acute bronchitis, and other infections can also cause fever. Children with croup or bronchiolitis may need a different assessment, especially if breathing is affected.

Rest, drink regularly, and wear light, comfortable clothing. Check the temperature with a working thermometer and keep a note of readings, symptoms, and any medicine taken. Use fever medicine only as directed on the label or by a clinician, and check ingredients to avoid taking the same medicine twice. Stay home while unwell and improve ventilation around others. Flu-like fever with a cough, sore throat, or body aches may overlap with COVID-19, so ask a clinician or testing service what is appropriate locally.

Seek urgent help for trouble breathing, chest pain, blue or grey lips, severe drowsiness, confusion, a seizure, or inability to keep fluids down. Contact a clinician promptly if fever is worsening, returns after improving, or occurs with a stiff neck, a spreading rash, severe weakness, or very little urine. Infants, older adults, pregnant people, and those with long-term medical conditions may need earlier advice. A clinician can decide whether examination, testing, or treatment is needed.

Could my symptoms fit flu or another infection? Which thermometer method should I use? How often should I check my temperature? Which medicines are suitable with my existing conditions or prescriptions? What warning signs should prompt urgent care?