Quick Answer
A fever is a temperature of 100.4°F (38°C) or higher — and in a baby, the age matters more than the number. Fever is not an illness; it’s your baby’s immune system fighting an infection, usually a harmless virus. But there is one rule you must never break: any fever in a baby under 3 months is a medical emergency — see a doctor the same day, even at night. For older babies, watch how your baby behaves, not just the thermometer. This guide tells you exactly what to do, what’s safe at home, and when to rush in.
⚠️ The under-3-months rule: If your baby is younger than 3 months and has a temperature of 100.4°F (38°C) or higher, do not wait, do not give medicine at home first — go to a pediatrician or hospital immediately. In tiny babies a fever can be the only sign of a serious infection.
What counts as a fever?
Fever is a body temperature of 100.4°F (38°C) or above. Normal baby temperature sits around 97–99°F (36.5–37.5°C) and shifts a little through the day.
| Reading | What it means |
|---|---|
| Below 100.4°F (38°C) | Not a fever |
| 100.4–102.2°F (38–39°C) | Low-grade fever |
| Above 102.2°F (39°C) | High fever |
| 104°F (40°C) or above | Very high — see a doctor |
A higher number does not mean a more serious illness. A baby can be quite sick with a mild fever and quite well with a high one. How your baby looks and behaves tells you far more than the thermometer.
How to take your baby’s temperature
- Digital thermometer in the armpit (axillary) is the easiest and safest method for home use in India. Hold the arm gently against the body until it beeps.
- For babies under 3 months, doctors often confirm with a rectal reading (most accurate) — but you don’t need to do this at home; if a young baby feels hot, just get them seen.
- Forehead (temporal) and ear thermometers are convenient but less accurate in small babies — fine for a quick check, but confirm a borderline reading.
- Avoid old mercury thermometers (breakage risk) and “feeling with your hand” as your only check — skin can feel hot from a warm room or crying.
When to see a doctor — the red flags
Get medical help the same day (or go to the emergency room if marked 🚨) if your baby:
- 🚨 Is under 3 months with any fever of 100.4°F (38°C) or higher
- 🚨 Is hard to wake, floppy, or unusually drowsy
- 🚨 Has difficulty breathing, fast breathing, or a sucked-in chest
- 🚨 Has a rash that does not fade when you press a glass against it
- 🚨 Has a fit/convulsion (seizure), a stiff neck, or a bulging soft spot
- 🚨 Has blue, grey, or very pale lips or skin
- Is 3–6 months with a fever of 102°F (39°C) or higher
- Has had a fever for more than 2–3 days, or it keeps climbing
- Is not feeding or has far fewer wet nappies than usual (a sign of dehydration)
- Is inconsolable, persistently vomiting, or just “not themselves”
When in doubt, get your baby checked. You will never be wrong to ask a pediatrician about a feverish baby.
Safe home care for fever
If your baby is over 3 months, alert, feeding, and otherwise comfortable, you can usually care for a mild fever at home:
- Keep them hydrated. Offer breast milk or formula more often (smaller, frequent feeds). For babies over 6 months, offer water and their usual foods.
- Dress light. One comfortable layer. Do not bundle a feverish baby in blankets — trapping heat makes the fever worse.
- Keep the room comfortable, not cold. A fan on low or normal ventilation is fine.
- Rest. Let your baby sleep as much as they want.
- Tepid (lukewarm) sponging only if your baby is very uncomfortable — never cold water, never ice, never alcohol rubs (these are dangerous and can cause shivering, which raises temperature).
Fever medicines — use carefully
Medicine is for comfort, not to force the number down. A child who is feverish but playing and drinking often needs no medicine at all.
- Paracetamol (acetaminophen) — the first choice, safe from early infancy. The dose is calculated by your baby’s weight (about 15 mg per kg per dose), not their age, usually every 4–6 hours.
- Ibuprofen — an option only for babies over 6 months who are well-hydrated, given with feeds.
- Always: dose by weight using the syringe/cup that comes with the bottle, never exceed the maximum doses in 24 hours, and confirm the exact amount with your pediatrician or pharmacist. Getting the dose wrong is one of the most common — and most preventable — reasons babies are harmed.
- Never give aspirin to a baby or child (risk of a serious condition called Reye’s syndrome).
- Do not routinely alternate paracetamol and ibuprofen unless your doctor specifically tells you to — it leads to dosing errors.
- Fever is not treated with antibiotics. Most baby fevers are viral; antibiotics don’t help viruses and overuse fuels resistance. Only a doctor decides if an antibiotic is needed.
Febrile seizures — frightening but usually harmless
Some children (most often between 6 months and 5 years) have a brief fever fit (febrile seizure). It’s terrifying to watch but is usually harmless and over within a couple of minutes. If it happens:
- Stay calm and note the time.
- Lay your baby on their side on a safe, flat surface.
- Do not put anything in their mouth or try to restrain their movements.
- Go to a doctor afterwards to find the cause.
- Call emergency services / go to the ER immediately if the seizure lasts more than 5 minutes, if breathing looks difficult, or if it’s the first one.
In the Indian context
- Many fevers in India are common viral illnesses, but some need testing — dengue, typhoid, malaria, and urine infections can all cause fever. If a fever is high, lasts beyond 2–3 days, or comes with warning signs, your pediatrician may advise blood/urine tests. Don’t self-medicate.
- Resist pressure to start antibiotics “just in case.” Let the doctor decide.
- Keep paracetamol at home, know your baby’s current weight, and save your pediatrician’s number — fevers love to spike at night.
Common fever myths
- “Teething causes high fever.” Teething may cause a slightly raised temperature and fussiness, but a true fever (≥100.4°F) is from an infection — don’t blame the teeth and miss something.
- “A very high fever will damage the brain.” A fever from an ordinary infection will not harm a healthy child’s brain. What matters is the cause and how your baby is coping.
- “Starve a fever.” No — keep your baby fed and, above all, hydrated.
- “Cold baths bring the fever down fast.” They cause shivering and distress and can backfire. Lukewarm only, and only for comfort.
Frequently Asked Questions
What temperature is a fever in a baby?
100.4°F (38°C) or higher. Below that is not a fever. But for any baby under 3 months, even this reading means see a doctor straight away.
My baby is under 3 months and has a fever — what should I do?
Treat it as an emergency. Do not give medicine and wait — take your baby to a pediatrician or hospital the same day, including at night. In young babies, fever can be the only clue to a serious infection.
How much paracetamol can I give my baby?
Paracetamol is dosed by your baby’s weight (roughly 15 mg/kg per dose, every 4–6 hours), not by age. Always confirm the exact amount with your pediatrician or pharmacist and use the syringe that comes with the bottle. Never give aspirin.
Should I give antibiotics for fever?
No — not unless a doctor prescribes them. Most baby fevers are viral, and antibiotics don’t work on viruses. Overusing them is harmful.
Is a high fever more dangerous than a low one?
Not necessarily. How your baby looks and behaves matters more than the number. A baby can be seriously unwell with a mild fever and perfectly fine with a higher one — which is why the red-flag signs above are what to watch.
Can I use tepid sponging to bring the fever down?
Lukewarm sponging can help with comfort if your baby is distressed, but never use cold water, ice, or alcohol — they cause shivering and can make things worse. Hydration, light clothing, and the right dose of paracetamol are safer.
This is general information for Indian parents, not a substitute for a consultation with your pediatrician. A feverish baby — especially under 3 months — should always be assessed by a doctor when any warning sign is present. Babynama’s pediatricians are available on WhatsApp if you need to talk to someone now.