Fever in a Newborn: When Is It an Emergency?

A fever in an older child is usually a manageable, self-limiting illness. A fever in a newborn or young infant is a completely different situation — it is a medical emergency until proven otherwise. Here is what every new parent in India needs to know.

What Temperature Is a Fever in a Baby?

A temperature of 38°C (100.4°F) or above is defined as fever in a newborn and young infant. Use a rectal or axillary thermometer (axillary reading is 0.5°C lower than actual core temperature).

Why Is Newborn Fever So Serious?

Newborns (0–28 days) and young infants (under 3 months) have immature immune systems. They cannot effectively fight serious bacterial infections such as:

• Sepsis (bloodstream infection)
• Meningitis (infection around the brain)
• Urinary tract infection (UTI)
• Pneumonia

These infections can progress from mild fever to life-threatening illness within hours in a newborn. The problem is that newborns often do not look very sick in the early stages — they may have fever as their only sign. This is why fever under 3 months requires immediate hospital assessment, regardless of how well the baby appears.

Age-Specific Guidelines

Under 28 days (0–4 weeks): Any fever is an emergency. Go to hospital immediately. Do not wait. Do not give paracetamol and observe. These babies need blood cultures, urine tests, lumbar puncture (spinal fluid test), and IV antibiotics started urgently.

1–3 months: Any fever requires same-day hospital assessment. If the baby appears very unwell (very drowsy, not feeding, breathing fast, looks pale or mottled), go immediately. If the baby looks reasonable, still go to hospital the same day — do not wait until tomorrow.

3–6 months: Fever above 39°C, or any fever with a baby who is very unwell, requires urgent assessment. Fever below 39°C in an otherwise alert, feeding, interactive baby can be monitored with contact with your paediatrician.

Warning Signs That Require Immediate Emergency Care at Any Age

• Fever in a baby under 3 months — any temperature 38°C or above
• Very drowsy, limp, or unresponsive
• Not feeding at all for more than one feed
• Fast breathing, laboured breathing, or noisy breathing
• Rash — especially a purple or reddish rash that does not fade when pressed (non-blanching rash)
• Fontanelle (soft spot on head) bulging or sunken excessively
• Seizure with fever (febrile seizure)
• High-pitched, inconsolable crying

What to Do While You Get to Hospital

• Keep the baby comfortable — undress to a vest if very hot, but do not over-cool
• Offer a feed (breast or bottle) to prevent dehydration if the baby will take it
• Do NOT give paracetamol (Calpol) to a baby under 2 months without medical advice
• Do NOT apply cold wet cloths or ice — this can cause dangerous shivering
• Go to hospital. Call ahead if possible.

Sri Anand Child and Neuro Center provides urgent paediatric assessment for febrile infants. Dr. Sushma B (DNB Paediatrics, PICU Fellow) is available during clinic hours. For after-hours emergencies, please proceed to the nearest emergency department. For urgent appointments: +91 90633 66983.