Fever is the single most common reason parents seek medical advice for their child — and also one of the most anxiety-provoking. Yet fever itself is not harmful; it is the body’s adaptive immune response to infection. Understanding when fever needs treatment, when it needs medical attention, and when it simply needs time is the most useful knowledge a parent can have.
What Fever Is and Why It Happens
Fever is defined as a body temperature of 38°C or above. It is triggered by pyrogens (fever-causing substances) released during infection or inflammation, which act on the hypothalamus to reset the body’s temperature set-point upward. This higher temperature is not a malfunction — it is a deliberate immune adaptation. Many viruses and bacteria replicate less efficiently at higher temperatures; immune cells (particularly lymphocytes) function better at elevated temperatures. Fever is the immune system doing its job. The goal of fever management is comfort — not the elimination of fever as if it were the illness itself.
How to Take a Child’s Temperature
Under 4 weeks: rectal temperature (digital thermometer) is most accurate in neonates. 4 weeks to 5 years: tympanic (ear) thermometer or temporal artery (forehead) thermometer — both accurate when used correctly. Underarm (axillary) measurement is less reliable (add 0.5°C to estimate core temperature). Over 5 years: oral thermometer is accurate; tympanic also reliable. Normal range: 36.4–37.4°C. Fever: ≥38°C. High fever: ≥39°C.
NICE Traffic Light System
NICE guidance uses a traffic light system to categorise fever risk: Green (low risk): normal colour, responsive, content, normal cry, normal moist mucous membranes, no red or amber features. Manage at home with oral fluids, comfort, and antipyretics as needed. Amber (intermediate risk — seek medical advice same day): pallor reported by parent, not responding normally, wakens with prolonged stimulation, reduced fluid intake, dry mucous membranes, fever for ≥5 days, rigors, swollen joint or limb. Red (high risk — emergency assessment): pale/mottled/ashen/blue colour, no response to social cues, very weak high-pitched or continuous cry, non-blanching rash, bulging fontanelle, neck stiffness, seizure, severe respiratory distress, fever in child under 3 months.
Treating Fever at Home
Antipyretics: paracetamol and ibuprofen both reduce fever and provide comfort. Age-appropriate doses (by weight, not age, for accuracy). Paracetamol: from 2 months (from birth if premature/low birth weight — discuss with pharmacist). Ibuprofen: from 3 months (minimum 5kg). Do not give both simultaneously, but alternating if fever is poorly controlled by one alone is commonly practised (pharmacist advice recommended). Do not use aspirin in children under 16 (Reye’s syndrome risk). Do not use cold sponging — produces rapid skin cooling that triggers shivering, which generates more heat and is distressing. Dress lightly; offer fluids regularly.
Frequently Asked Questions About Childhood Fever
Should I treat a fever if my child seems well?
If a child has a fever but is reasonably comfortable, active, drinking, and not showing red or amber signs, antipyretic treatment is optional — it improves comfort but doesn’t alter the course of the illness. The child’s overall clinical appearance (behaviour, responsiveness, hydration) matters far more than the temperature number.
Is a febrile seizure dangerous?
Febrile convulsions (seizures triggered by rapid fever rise) affect approximately 3% of children aged 6 months to 5 years. They are frightening to witness but are not dangerous in themselves — they do not cause brain damage and do not predict epilepsy in most cases. If your child has a febrile seizure: lay them on their side, stay calm, time the seizure, call 999 if it lasts more than 5 minutes or if this is the first episode. After recovery, seek medical assessment to identify the source of fever.
Can I give children’s paracetamol and ibuprofen together?
Not simultaneously — this provides no additional benefit and increases medication risk. Alternating them (e.g. paracetamol, 4 hours later ibuprofen, 4 hours later paracetamol) can be appropriate if fever is not controlled by one agent alone — but discuss this approach with your pharmacist or GP first.
Browse children’s medicines including age-appropriate paracetamol and ibuprofen at Huncoat Pharmacy. Related: Paracetamol vs Ibuprofen.
At Huncoat Pharmacy: Pharmacy First for children, Browse children’s fever & pain relief, NHS children’s services.