Why your baby's age matters so much

This is the bit worth screenshotting. The NHS page on high temperature in children says to call 111 or ask for an urgent GP appointment if:

• your baby is under 3 months and has a temperature of 38C or higher, or you think they have a high temperature
• your baby is 3 to 6 months and has a temperature of 39C or higher, or you think they have a high temperature
• they have other signs of illness alongside the temperature, such as a rash
• the high temperature has lasted 5 days or more
• they aren't feeding or aren't acting like themselves, and you're worried
• they show signs of dehydration, such as fewer wet nappies, sunken eyes or no tears when crying

Under 3 months, 38C isn't a wait-and-see number. It's a call-111 number.

When to call 999 or go to A&E

The NHS says to call 999 or go to A&E if your baby has a high temperature and they:

• have a stiff neck, or a rash that doesn't fade when you press a glass against it
• seem bothered by light
• have a fit (a febrile seizure) for the first time
• have unusually cold hands and feet
• have skin that has changed colour, or blue, grey or pale lips or tongue
• are drowsy and hard to wake
• are extremely agitated and won't settle, or seem confused
• are finding it hard to breathe, are grunting, or are breathing fast
• aren't responding normally, or aren't interested in feeding

Looking after a baby with a temperature at home

Most babies with a high temperature can be looked after at home, and the NHS says it usually comes down within 1 to 4 days.

• Keep the feeds coming. Offer plenty of fluids, and if you're breastfeeding, keep going and offer feeds more often.
• Don't bundle them up. The NHS says not to overdress a child with a temperature or pile on blankets, and the Lullaby Trust says not to be tempted to wrap an unwell baby up more than usual. Dress them for the room you're in.
• Don't strip them off or sponge them down either. A high temperature is a natural response to infection, and the NHS advises against both.
• Check on them regularly, including overnight, and keep an eye out for signs of dehydration.

Paracetamol and ibuprofen: the age rules

Medicine is for when your baby is distressed or uncomfortable, not just to chase a number down. The NHS rules for young babies are specific, so it helps to know them before the pharmacy shuts:

• No paracetamol under 2 months. From 2 to 3 months, the NHS page on paracetamol for children says babies can have infant paracetamol if they weigh over 4kg and were born after 37 weeks. Babies this age can also have up to 3 doses after their MenB vaccinations to help prevent a high temperature (our guide to your baby's first jabs has more on that).
• No ibuprofen under 3 months, or for babies under 5kg. The NHS also says not to give it to a child with chickenpox or who is dehydrated, or to a child with asthma unless a doctor recommends it.
• Don't alternate the two unless a health professional tells you to, and never give aspirin to anyone under 16.
• Check the packet every time. Doses depend on age, so use the syringe that comes with the bottle, and ask a pharmacist, GP or health visitor if you're unsure, or if your baby was born early.

The bit to remember

You know your baby better than any thermometer does. If they seem unwell in a way you can't quite put your finger on, get advice, whatever the number says. Calling 111 about a hot, grumpy, off-their-feed baby is exactly what it's there for.

Temperatures often arrive with a runny nose: here's what's normal with your baby's first cold, what to know about RSV this winter, and how to dress a newborn for autumn without overdoing the layers.

This article is general information based on NHS and Lullaby Trust guidance, not medical advice. If you're worried about your baby, trust your instincts and call NHS 111, your GP, or 999 in an emergency.