What Is A High Fever In A Child?

With all the focus right now on fever due to the COVID-19 outbreak, parents are asking “What is a high fever in a child?”

NHS guidelines state that normal temperature for babies and children is around 36.4C but as this is an average, it is a good idea to know your own child’s normal body temperature.

Nurse Taking Crying Baby’s Temperature With Digital Thermometer


Taking Your Child’s Temperature

Using an in-ear thermometer, which are generally regarded as the most accurate device to use, follow this method:

  1. Take the child’s temperature using the same device in the same place (e.g. right ear) at the same time of day for seven day.
  2. Work out the mean temperature (add the temps together and divide by 7)
  3. If the chld gets ill and the temperature elevates more than 0.3-0.4C on any of those days, discount that temperature from the calculation.

Once you have this data, you are better equipped to make good decisions about what to do when the temperature varies.

Normal body temperature

Since 36.4C is the average, it follows that some children will normally have a lower temperarture and some will have a higher temperature.

NHS goes on to say that a fever is any temperature of 38C and over. So, effectively a 1.5C degree rise from normal or thereabouts. However, in babies under 3 months of age, we know that the body’s ability to regulate temperature is immature. In fact that’s true for older children too,but particularly so in newborns. Therefore a 1C rise should trigger awareness of the need to monitor carefully for any other signs of illness.

If your child’s temperature is usually on the low side – say 36.0C and they go up to 37.6C, this could be a sign of illness. A NHS professional is unlikely to be concerned because they are working from a higher starting point. You are the expert in your child and you can use your better data to trigger medical assistance if you feel its needed.

If your child normally has a higher than average temperature, this is also worth knowing. perhaps they are normally 37.2C and they go up by 1C. This could trigger caregivers to want to treat with medication, when in fact, it might be better to have the child’s body deal with it. Overuse of medications such as Calpol can lead to a prolonged illness because the body isn’t getting hot enough to kill the bug. An eye-opening documentary on the use of Calpol in the UK reported that many parents are giving this medication purely for fever (and low grade fevers as well) rather than for pain, which is the intended use.

So, what is a dangerously high fever?

Babies and children up to age 2 are more likely to suffer from febrile seizure – a seizure caused by a spike in body temperature. This is because our internal thermostats aren’t fully functioning in the early months of life. It is the rapid change in temperature which causes the seizure rather than the absolute peak of the temperature per se.

A body temperature of over 39.5C in infants and young children is usually caused by an infection (although teething and environmental reasons can also cause this). Fevers above 39C often come with other signs and symptoms of infection and it’s definitely worth taking medical advice if you are worried at all about your child.

Dangerously high fevers that could lead to brain damage occur above 42C (108F) and at above 44C many people will not survive.

Treatment of high fever

Where the temperature is up to 1.5C above normal temperature:

  1. Cool the environment but don’t put the child right next to a cold air source
  2. Remove excess clothing and cover with a light sheet or muslin for a baby
    • Cold air on feverisg skin causes shivering – so cover them lightly to reduce this.
  3. Cool with a cold flannel on forehead or back of neck (do not put the child into a bath or shower of cold water)
  4. Give plently of fluids
  5. Consider medication if the child is clearly in pain (i.e. from teething, headache or sore throat etc)
  6. Allow to rest

Where the temperature is greater than 1.5C above normal:

  1. Follow point 1-4 as above
  2. Consult a healthcare professional for more advice

Where the temperature is above 40C:

  1. Follow point 1-4 as above
  2. Consult a healthcare professional for more advice
  3. Take to A&E if there are symptoms which suggest more severe infections such as meningitis.
    1. For a helpful resource, go to Meningitis Now and download the app.

So in summary – important things to know about fever in children:

  1. Normal body temperature is around 36.4-36.5C
  2. Work out your child’s normal body temperature
  3. Cool a child down -remove clothing, cool the environment, cold flannel on head
  4. Give fluids
  5. Call for advice when temperature reaches 1.5C over normal with other symptoms or above 40C with no other symptoms.

I’m interested to know what you do when your child has a high temperature. Please get in touch and comment below.

For information on my baby and child first aid courses, check out my site here or email me on michelle@parentpartner.co.uk