Children's Health

Fever in Children: When to Worry

Fever is the body's normal response to infection, but knowing when it signals something serious is essential for parents.

Normal temp
36.1–37.2°C
Fever threshold
≥38°C
Call 999 if
Under 3 months + fever
Most common cause
Viral infection

Traffic Light System (NICE)

CategorySigns
Green (low risk)Normal colour, responds normally, content, normal breathing
Amber (intermediate)Pale, decreased activity, poor feeding, dry mucous membranes
Red (high risk)Pale/mottled/blue skin, no response, weak cry, grunting, reduced skin turgor

When to Take Your Child to A&E

Tests Doctors May Order

TestPurpose
FBCCheck for bacterial infection (raised WBC) vs viral
CRPBacterial infection marker
Urine dipstick/cultureUTI is a common hidden cause of fever in young children
Blood cultureIf sepsis suspected
Chest X-rayIf breathing symptoms present
Meningitis Warning SignsNon-blanching rash, stiff neck, unusual drowsiness, high-pitched crying, bulging soft spot (infants). Press a glass against the rash — if it doesn't fade, call 999 immediately.
Fever ManagementParacetamol or ibuprofen can help comfort, but fever itself is not dangerous unless very high (>40°C) or the child seems very unwell. Dress lightly, offer fluids, and don't over-bundle.
Should I always give medicine for fever?
Only if your child is uncomfortable. Fever helps fight infection. Treat the child's comfort, not the number on the thermometer.
Can teething cause high fever?
Teething can cause a very mild temperature rise but not a true fever (>38°C). Any real fever needs another explanation.
How long can a viral fever last?
Most viral fevers resolve within 3–5 days. If fever persists beyond 5 days, seek medical review.
Medical Disclaimer: This page is for general education only and does not replace professional medical advice. Always consult a qualified healthcare provider.