Baby fever: when it is an emergency and when you can manage at home
Updated
A fever is not an illness in itself but a sign that the body is fighting something, most often an infection. In babies it is more frightening than in adults, and for good reason: the younger the child, the less you can rely on "looks fine" and the more it matters not to lose time.
Below: what counts as a normal temperature and what counts as a fever, what to do at home, what to avoid and, most importantly, the cases where hours matter. We start with the one rule to learn before all the others.
The key rule: a baby under 3 months
In a baby younger than 3 months, a temperature of 38 °C or higher is a medical emergency. Seek medical care immediately, even if the baby otherwise looks well — calm, feeding, smiling. The immune system at this age is immature, and a serious infection can run with almost no outward signs until it becomes dangerous.
Do not wait "until morning" and do not bring the temperature down to "see how it goes". At this age the fever itself is reason enough for an urgent examination by a doctor.
What is a normal temperature, and what is a fever
A normal body temperature is about 36.5–37.5 °C. It varies through the day, is usually a little higher toward evening, and depends on how the child is dressed, whether they have been active and whether they have overheated. A fever means a temperature of 38 °C or higher.
It is important to understand: the number alone is not a diagnosis. A high temperature does not automatically mean a serious illness, and a mild one does not guarantee that all is well. In a baby, the age of the child and how they behave and feel matter far more than the absolute figure.
How to measure the temperature properly
In infants, a rectal reading is considered the most accurate. Do it gently: lay the baby on their back or side, lubricate the tip of the thermometer, insert it only very slightly and hold it in place until the thermometer gives a result. Never restrain the baby by force and never insert the thermometer deeply.
The method affects the number: an armpit reading is usually lower than a rectal one, and ear and forehead thermometers are less reliable in the youngest babies. When you give a temperature to a doctor, always say how you measured it — it changes how the figure is read.
What to do, by age
| Age | What a fever means | What to do |
|---|---|---|
| Under 3 months | Any temperature of 38 °C or higher is an emergency | Seek care immediately, without delay |
| 3–6 months | Needs a doctor’s assessment | Contact the doctor the same day |
| 6–24 months | Judge by how the child is, not by the number | Keep them comfortable and offer fluids; see a doctor if the child is unwell or the fever lasts longer than 24–48 hours |
| Over 2 years | Usually managed at home by easing discomfort | Keep them comfortable; see a doctor if the child is unwell or the fever persists |
What you can do at home
- Do not overheat. Dress the child lightly and cover them with a light sheet rather than a warm blanket. Too much clothing stops the body from giving off excess heat.
- More fluids. Offer the breast or formula more often than usual, and water for older children. A fever makes the body lose more fluid, and the main thing is to prevent dehydration.
- A fever reducer, when indicated. Give children’s paracetamol or ibuprofen only at a dose for the child’s age and weight and on a doctor’s advice. The aim is to ease discomfort if the child is suffering, not to force the number down at any cost.
- Rest and watch. Let the child rest and keep a close eye on how they feed, drink, wet their nappies and behave between the rises in temperature.
What not to do
- Do not bundle the child up or cover them with a warm blanket to "sweat it out" — that only traps heat and pushes the temperature higher.
- Do not sponge with cold water, do not put them in a cold bath and never rub with alcohol or spirits — it is dangerous and causes the blood vessels to constrict and the child to shiver.
- Never give a child aspirin — in children it is linked to a rare but life-threatening injury to the liver and brain (Reye’s syndrome).
- Do not give several fever reducers at once and do not exceed the dose if the temperature "will not come down" — count the time between doses and do not combine medicines without a doctor’s instruction.
- Do not blame a high temperature on teething. Teething can cause a slight rise but does not cause a true fever — at 38 °C or higher, look for another cause.
When to seek urgent help
Call emergency services or seek a doctor urgently at any age if, with the fever, the child shows any one of these signs: they are hard to wake, very drowsy or floppy; they are struggling to breathe; a rash appears that does not fade when you press on it (check it with a clear glass); a stiff neck or a bulging soft spot; a seizure; signs of dehydration — few wet nappies, crying without tears, sunken eyes; the child is inconsolable or behaving very unusually; the fever lasts more than about 5 days.
And to repeat the key point: in a baby younger than 3 months, any temperature of 38 °C or higher needs immediate care, even without any of these signs.
How a record helps you and the doctor
With a fever it is easy to lose track: when it started, how high it peaked, when and what you gave. If you note the thermometer readings, the times you measured and any medicine given, you can see the trend — whether the temperature is rising or falling — and tell the doctor not "it was high" but exactly what happened and when. For a treatment decision, that matters far more than one random figure.
Baby Tracker keeps these records for you
Feeds, sleep and nappies in two taps, a day-by-day view of the routine, and shared access for the whole family. Free, right inside Telegram — no install, no sign-up.
Open in TelegramFrequently asked questions
What counts as a normal temperature in a baby?
About 36.5–37.5 °C. It varies a little through the day and is usually slightly higher toward evening. A temperature of 38 °C or higher is considered a fever.
What should I do if a baby under 3 months has a fever?
In a baby younger than 3 months, a temperature of 38 °C or higher is a medical emergency. Seek medical care immediately, even if the baby looks well. Do not wait and do not try to bring the temperature down yourself first.
How do I measure a baby’s temperature correctly?
In infants a rectal reading is the most accurate — gently and only very slightly inserted. The method affects the number: an armpit reading is usually lower, and ear and forehead thermometers are less reliable in the youngest babies. When you tell a doctor, say how you measured it.
Do I always have to bring a fever down with medicine?
No. A fever reducer is there to ease discomfort if the child is suffering, not to reach a "normal" number. Give children’s paracetamol or ibuprofen only at a dose for the child’s age and weight and on a doctor’s advice. Never give a child aspirin.
Can a high fever be caused by teething?
Teething can cause a slight rise in temperature but does not cause a true fever. If a child has 38 °C or higher, do not blame it on teeth — look for another cause and see a doctor if needed.
Sources
This article is for general information and does not replace medical advice. In a baby younger than 3 months, any temperature of 38 °C or higher needs immediate care. Give fever reducers only as directed by a doctor and at a dose matched to the child’s age and weight. Discuss any concern about your child’s health and wellbeing with your own doctor.