What should you know about prolonged fever?

Fever is the body's response to a problem, commonly an infection. Respiratory infections such as a common cold, COVID-19 or acute bronchitis may cause it, while bronchiolitis and croup are more relevant in young children. Other possible causes include cellulitis, chickenpox and infections acquired through food, animals or travel, such as brucellosis. Fever alone cannot identify its cause; associated symptoms and examination guide the next step.

Rest, drink fluids regularly and wear light clothing in a comfortable room. Use a thermometer consistently and record the readings, timing, medicines and accompanying symptoms. Take only fever medicine that is suitable for you and follow its label or clinician's instructions; do not give children medicines intended for adults. Arrange a medical review when fever persists, keeps returning, or occurs in someone with a serious long-term illness or weakened immunity.

Get urgent help for difficulty breathing, a stiff neck, confusion, a seizure, severe headache, a purple or rapidly spreading rash, repeated vomiting, severe dehydration or unusual drowsiness. Infants, older adults, pregnant people and anyone with reduced immunity may need earlier advice. Seek emergency care when the person looks seriously unwell, regardless of the thermometer reading.

Ask what source of fever is most consistent with your other symptoms, whether an examination or tests are needed, which fluids and medicines are appropriate, and what changes should prompt urgent reassessment. Mention travel, animal contact, new medicines and recent infections.