Updated August 25, 2026
Babies cannot tell us what hurts, so the most useful clues are changes from their normal pattern: feeding, breathing, alertness, colour, temperature, wet diapers, sleep, and how easily they can be comforted. Trust your knowledge of your baby and seek care when something feels seriously wrong.
Important: This article provides general information, not a diagnosis. If your baby has trouble breathing, is blue or grey, is very difficult to wake, has a seizure, or you believe the situation is an emergency, call emergency services.
Check temperature accurately
A measured temperature of 38°C (100.4°F) or higher is a fever. SickKids advises that a baby younger than three months with a fever needs immediate assessment by a health-care provider. Use a thermometer rather than touch alone, and follow the thermometer instructions for your child’s age.
Watch feeding and hydration
Call a health-care professional if your baby will not feed, repeatedly vomits, cannot keep fluids down, has far fewer wet diapers than usual, has a dry mouth, or appears dehydrated. Small, frequent feeds may be easier when a baby is mildly unwell, but urgent warning signs should not be managed only at home.
Pay attention to breathing and alertness
Urgent signs include struggling for breath, grunting, pauses in breathing, ribs pulling in with each breath, a blue or grey colour, unusual limpness, confusion, or being difficult to wake. A baby who is less playful may simply be tired, but a major change in responsiveness deserves prompt medical advice.
Look at the whole child
The number on the thermometer is only one part of the picture. SickKids notes that how a child looks and acts is especially important. Record the temperature, when symptoms began, feeds, wet diapers, medication given, and any rash so you can give a clear history.
Get advice when you are unsure
For non-emergency concerns, contact your baby’s health-care provider or local nurse advice line. In much of Canada, 811 connects callers with health advice. Medication doses for babies depend on age and weight; ask a clinician or pharmacist before giving medicine, especially to a young infant.
