What should you know about types of fever?

A short-lived fever may settle as an infection improves. A continuous fever stays raised with only small changes, while a recurrent fever returns after periods of improvement. Chills, sweating and feeling hot can occur as the body’s temperature regulation changes, so symptoms alone do not measure temperature reliably.

Fever may accompany respiratory illnesses such as a common cold, acute bronchitis, bronchiolitis or croup. Skin changes can occur with chickenpox or cellulitis, and some infections such as brucellosis have a more prolonged course. COVID-19 is another possible context. The presence of fever does not identify one cause by itself.

Use a reliable thermometer and note the reading, time and accompanying symptoms. Encourage fluids and rest, dress lightly, and avoid cold baths or excessive covering. If the person is uncomfortable, ask a pharmacist or clinician about a suitable fever medicine and follow its label or prescription directions. Keep children away from school or nursery according to local advice while they are unwell.

Seek urgent care for difficulty breathing, blue or grey lips, severe dehydration, confusion, a seizure, a stiff neck, a rapidly spreading rash, or unusual difficulty waking. Get prompt medical advice for a very young infant with fever, an older or medically vulnerable person, fever after recent travel, or a fever that persists or repeatedly returns. A child who looks seriously unwell needs assessment regardless of the thermometer reading.

Ask what cause best fits the fever pattern, whether an examination or test is needed, how much fluid to offer, which medicine is suitable, and which changes should trigger same-day or emergency review.