A fever is when the body’s temperature is increased and is a sign that it is fighting an illness like an infection or virus. A fever means that the immune system is doing what it needs to do. The normal body temperature is 37°C; for adults, a temperature that’s below 39°C isn’t usually cause for concern.

However, a fever in infants and toddlers is a different story, as young children’s bodies have more difficulty regulating temperature – even a slight fever can mean there’s something serious going on. Here are a few things to keep in mind if your baby or tot is running a temperature…

It’s 38.5°C or over

A fever that’s even a little above 37°C needs to be watched. As always, trust your gut: if you suspect your little one of being ill you should first take their temperature (a rectal thermometer gives the most accurate results, so it’s a good idea to have one at hand). This is especially important if your baby seems listless or hot. If your baby's temperature exceeds 38.5°C, contact your doctor.

If your baby is running a slight fever you can also try the following:

• Remove some clothes
• Keep the room cool
• Cover baby with a sheet only
• Offer frequent small feeds (older babies need plenty of water)

When to see a doctor

If your little one is younger than three months, even a slightly raised temperature may be a sign of a serious problem. It’s best to go to the GP if you have any concerns, especially if baby seems unusually irritable, lethargic, and seems generally unwell.

If a fever lasts longer than 24 hours in a baby younger than two years old, and there are no other symptoms, then you need to see a GP – the same applies if the fever doesn’t lower with medication, or if your little one seems to be dehydrated. 

Children between the ages of six months and five years may have seizures that are caused by fevers (called febrile seizures); usually your child will be fine after having one, but if this does happen you’ll need to go to the doctor straight away to be on the safe side.

Most mild fevers aren’t a serious cause for concern: things like minor ear infections, teething, and wrapping baby in too many blankets can all raise the body’s temperature. But it’s always best to speak to a professional if you’re at all worried.