TempoLife › Features › Fever and childrens medicine dosing by weight › when-to-call
When to call instead of waiting
The red flags that override the thermometer — by age, and the combinations that are always urgent.
This is a reference, not a prescriber: the package insert of the bottle in your hand outranks every number on this page, aspirin is never for children, and in a baby under three months any measured fever is urgent — call now, do not dose. If the child is on other medicines, or has a known liver, kidney or stomach condition, dosing belongs to a clinician.
The age rules first
Under three months: any measured fever is urgent — call now. Three to six months: any fever above 38.5 °C, or any fever with poor feeding, drowsiness or a rash. Any child: a fever that has lasted more than three full days, whatever the temperature, because the differential changes with time.
The combinations that are always urgent
Fever with a rash that does not fade when pressed with a glass; fever with a stiff neck or light hurting the eyes; fever with fast or laboured breathing, or the skin pulling in between the ribs; fever with a seizure; fever with drowsiness that resists waking, or confusion; fever with signs of dehydration — no tears, dry mouth, no wet nappies for 8 hours or more, sunken eyes in a baby; fever after returning from travel in a malarial region.
The child, not the number
The single most useful skill is reading the child behind the fever. A feverish child who is miserable but alert, drinks, watches the room and perks up briefly is the normal picture. The child who lies limp, cannot be engaged, will not drink and looks at nothing is the urgent picture — at 38.5 °C or 39.5 °C alike.
Who you are calling
The routes differ by country and time of day: the family doctor or nurse line in office hours, the national medical helpline in the evening (staffed by nurses who triage), and emergency services for the urgent combinations. Have the child's age, weight, temperature readings and the medicines already given ready before you call — the person on the line will ask for all four.
Fever thresholds and red flags: the national paediatric guidance in the region. Dosing: the standard weight-based rules — paracetamol 15 mg/kg per dose every 4–6 hours, at most four doses a day (60 mg/kg/day ceiling); ibuprofen 10 mg/kg per dose every 6–8 hours, at most three doses a day (30 mg/kg/day ceiling), from 3 months and about 5 kg. Febrile seizures: the standard paediatric emergency guidance (simple vs complex, the five-minute line). Checked 2026-09-06.
Frequently asked questions
How many days of fever is too many?
Three full days is the standard line: a fever running past 72 hours needs a medical look whatever the temperature, because the list of causes changes. With the urgent combinations on this page, the line is not three days but now.
Should I go to the emergency department for a high fever?
Not for the number alone. Emergency care is for the urgent combinations — breathing trouble, the non-fading rash, the stiff neck, the child who cannot be roused. A high fever in an otherwise well child belongs to the family doctor or the helpline, who will tell you if it does not.
The rest of the fever pages
Fever at every age
All seven fever pages, with the thresholds, the ladders and the red flags.
What counts as a fever at each age
The measurement thresholds, why the site matters, and the one age where any fever is urgent.
Measuring temperature: which thermometer at which age
Rectal is the reference, the armpit is the compromise, and the ear is only as good as its aim.
Paracetamol dosing by weight
15 mg per kilogram per dose, every 4–6 hours, four doses a day at most — with the arithmetic worked.
Ibuprofen dosing by weight
10 mg per kilogram per dose, every 6–8 hours, from 3 months and about 5 kg — and the situations where it is the wrong choice.
A medicine log that answers the call
TempoLife timestamps every dose so the daily ceilings stay visible and the doctor gets exact numbers instead of a guess.