Fever in babies and infants

Having a sick baby is a scary thing. They can’t tell you what’s going on and it’s not always possible to gauge how ill they are just by looking at them. Fortunately, there are some hard and fast rules about when to call the doctor for a sick baby. Read on to find out when to take your baby or toddler to the doctor for a cough or fever, and when you can safely treat it at home.

How to tell if baby’s sick

Fever is an important indicator of illness, but visual and behavioural cues can sometimes give you more of a sense of how sick your child actually is. If they are, you’ll likely see at least a few of these symptoms:

• Clinginess
• Fussing or crying more than usual
• Fever
• Sleeping more than usual
• Lethargy, low energy
• Decrease in appetite
• Flushed or abnormally pale skin
• Coughing or wheezing
• Runny or snotty nose
• Diarrhea, loose stool or vomiting
• Rash

It can be hard to distinguish between the symptoms of cold, flu and COVID-19. Check out our handy primer for help comparing symptoms.

How high is too high for a baby fever?

Most babies will get a fever at some point in their first year, but in their first three months and especially the first 30 days, having a fever can be quite serious. Normal body temperature is 37 degrees celsius and anything above 38 is considered a fever, so if your baby is under three months and has a temperature over 38 degrees celsius, they need medical attention. At this age, a fever might be symptomatic of a dangerous infection. Fevers in infants between three and six months are generally less concerning, but it’s a good idea to connect with their doctor anyway, to rule out anything serious. Just to complicate matters, however, an infection can sometimes cause an infant’s temperature to drop below 37 degrees. That’s why it’s so important to look for other symptoms of illness — temperature doesn’t always tell the whole story.

How to treat fever in babies

As long as your child is at least six months old, you can give them baby Tylenol or Advil to bring their fever down. You can also cool your child down by removing extra clothing or their sleep sack and by wiping their forehead or the back of their neck with a cool washcloth. But no matter how much your grandma swears by it, NEVER try to bring your child’s fever down by giving them an ice bath. Not only is it ineffective, it’s also dangerous — babies can’t regulate their body temperature that well and an ice bath risks causing hypothermia, which can lead to death.

How to treat fever in infants

If your child is younger than six months, you’ll need to consult with their doctor first before giving them baby Advil or Tylenol. Offer your baby their bottle or your breast regularly when they’re sick to make sure they’re taking in lots of fluids. The risk for dehydration increases when children are sick, so keep an eye on the number of wet diapers they’re producing (at least six a day for infants). And if you’re at all concerned, speak to a doctor right away — dehydration in infants is quite serious and potentially life threatening. Never give a baby, child or teenager Aspirin or Acetylsalicylic acid (ASA) as it can cause Reye’s syndrome — a serious and sometimes fatal condition.

Baby’s first cold

When your baby gets a cold their runny nose can last for a while, making it seem like they’re sick forever. But how long does a baby cold actually last? In reality, most babies are over the worst of their symptoms after a few days. You might find, however, that your little one needs their nose aspirated and/or wiped for up to three weeks after they first get sick.

How to treat your baby’s cold

Sleep is an important part of treating your baby’s cold at home. Luckily, figuring out how to get a sick baby to sleep isn’t always harder than getting a well baby to sleep. Increased sleep needs often go hand-in-hand with illness, making your little one more likely to nod off during a feed or even in the middle of an activity. It’ll get more difficult, however, if they’re at all uncomfortable. Many parents find that a nasal aspirator and saline solution are essential during their child’s first 18 months as babies can’t blow their own noses at this age. When it comes to clearing congestion, recommendations are likely different than they were when you were growing up. Products like Vicks vaporub are no longer recommended for children under two, as they may cause inflammation and airway obstruction. Likewise, OTC cough medicine is a no-no for children under six. Instead, try running a humidifier in their room. This should help with any congestion they might have.

When to see a doctor

It is always a medical emergency if you think your baby may be having trouble breathing. The same goes if their lips or nails take on a bluish tinge, which can indicate low blood oxygen levels. In both cases, dial 9-1-1 immediately. In non-emergency cases, you should still see a doctor, however, if:

• Your child’s fever has lasted longer than 72 hours
• Their fever breaks and then returns
• You suspect your child is dehydrated
• Your child seems lethargic 
• Your child has a fever and is under six months
• You’re at all concerned about their behaviour or feel like something is “off”

You’re not going to be completely able to keep your baby from getting sick. But with the right info you can find yourself prepared for when it does happen. Practice good hand hygiene and make sure that their vaccines are up to date. Most baby illnesses run their course within a few days without complications. But if you’re at all worried, don’t hesitate to speak to a doctor or pediatrician.