Clinical FeaturesPaediatrics

Acute Paediatric Fever Advice: ‘Fever is mostly one of the Good Guys’

What is a fever?

Fever is a common symptom that can incite fear and worry in many parents. In practice, it is one of the most frequent reasons for health care attendance.1

A fever is a binary entity, it is a temperature of greater than or equal to 38.0°C. There has been a shift away from the concept of a “low grade” fever. In Ireland there is much variation in the knowledge on what is the actual definition of a fever.2, 3 Remember that an error with the definition can cause much confusion and unnecessary worry. If this is not clarified, this can sometimes expose the patient to an unnecessary medical visit and all that ensues.


There is a vast array of products to assess temperature, however some are more accurate than others. In the <1yr old population, an axillary thermometer is recommended, whereas at older ages a digital ear probe is both fast and accurate.4 Infrared thermometers, glass thermometers and forehead strips should be discouraged as they are less reliable. Again, a falsely positive temperature could result in children, in the interest of safety, being subjected to several potentially unnecessary investigations (e.g. Lumbar puncture, vascular access etc).

For the parent in the middle of the night, who can’t recall where the thermometer is, we have a natural gauge quite literally at our fingertips. Tactile assessment of temperature has been shown to be a sensitive measurement, though it is the least accurate way in terms of establishing a definitive quantity. Palpation of the chest and back is preferred to the forehead.

Common Questions to be addressed

Q. Fever is dangerous?

Answer: No. Fever is the body’s natural response to infections. It represents immune response activation and an indicator of an illness. The presence of a fever in of itself doesn’t require treatment with antipyretics. Observational trials in humans suggest a survival benefit from fever. The heat of fever augments the performance of immune cells, induces stress on pathogens and infected cells directly, and combines with other stressors to provide a nonspecific immune defence.

Q. Does the height of fever indicate the severity of illness?

Answer: False. A worry for parents is the upper limit of the temperature. While it is natural to assume a proportional severity to the degree of temperature, there is in fact no correlation between the temperature height and how ill the patient is. A child could be critically unwell with a temperature of 38.1°C, whereas another child could develop a 40°C fever and only experience a mild illness.5

Q. Is a failure to respond to antipyretics an indicator of severity of illness?

Answer: In a similar vein, the fact that a temperature does not resolve with antipyretics does not indicate a more severe illness. A child could have a consistent temperature for hours despite antipyretics and have a mild viral illness.

Q. How long is too long to have a fever?

Answer: Parents often worry about the duration of a fever. It is recommended that a child with a daily fever for 5 consecutive days seek medical attention. These patients have a higher incidence of serious bacterial infection and warrant a clinical assessment. In cases where antibiotics have been prescribed and indicated, it would be typical for the fever to resolve within 2-3 days of commencing antibiotic therapy. A fever that has not resolved after this duration of treatment would also be another indication for medical review.

Q. Will the fever cause a seizure?

Answer: This quite often leads to the discussion surrounding febrile convulsions and fevers. It is true that febrile convulsions occur in the setting of a febrile illness, however the risk of convulsion is not just related to fever. Rather, it is the genetic component that is a greater factor in the development of febrile convulsions. Indeed, teaching would discourage parents from actively avoiding temperatures to prevent convulsions, as the fever itself does not cause harm to the child.

Q. What should I look out for?

Answer: The important aspect to recognise in each acute febrile episode is the overall clinical condition of the child. Are they dehydrated, lethargic, poorly responsive, tolerant of oral intake or have a non-blanching rash? These are far more sensitive markers of severity of illness in the context of a fever.

Q. Does my child have sepsis?

Answer: One should always be vigilant for sepsis. As per the HSE, sepsis is life-threatening organ dysfunction caused by a dysregulated host response to infection. Fever in isolation does not automatically translate to sepsis, and few infections will develop into sepsis. There is no single test that detects sepsis, but as we will outline below it is the constellation of symptoms in the setting of an infection that invokes the diagnosis of sepsis. If you are concerned your child has sepsis, medical attention should be sought. It is always an important question to ask in the setting of fever.

For a public video resource see the following HSE Sepsis Public Awareness information: Sepsis Awareness by Health Service Executive (HSE) Ireland; Available from Youtube HSE Ireland Paediatric Sepsis Awareness

( watch?v=U0yqqkxsn_8 and who/nqpsd/qps-improvement/ sepsis.html).

When to be more concerned and seek help

As mentioned above, there are times when a fever is cause for greater concern. This is when there is:

  • Rapid breathing
  • Lethargy or difficult to rouse
  • No urine passed in the last 12hrs
  • Dehydration (dry lips, sunken eyes, decreased wet nappies or concentrated urine)
  • The presence of a bruising rash that does not go away when pressed
  • Convulsion
  • Cold to touch despite the temperature
  • The appearance of poor skins perfusion

In these situations, it is recommended that the parent seeks urgent medical attention.6

There is one further scenario in which we would encourage parents to seek medical attention and that is:

  • If their parental instinct tells them something is seriously wrong

Parents have a great sense of their child; their concern should never be disregarded and should be regarded as key information to inform the situation.

At risk populations:

There are several groups of children that are at higher risk of infection, and these can present differently. A higher degree of caution is required. These include those with disabilities with cognitive impairment or communicative difficulties. Children that have these conditions are more susceptible to infections such as pneumonia or urinary tract infections. These vulnerabilities are compounded by factors such as immobility or medical device dependence which can be another potential source of infection to consider. Communication can be an issue, and the child may convey their symptoms in ways that are only recognised by a carer and underappreciated by clinical staff. This underpins the need for the parent’s (or caregiver’s) input as they know the child well and are familiar with the nuances of their behaviours.7

A low threshold is reserved for those that are immunocompromised or neutropenic.8 As their immune systems are compromised, they don’t mount the same response to infection. A fever associated with these conditions could potentially be life-threatening, and prompt investigation and treatment is mandated under these circumstances.9

The final types of patients that we would consider “at risk” are the newborn and young infant.

Small baby rules (6 months and younger)

The above advice pertains to children older than 6 months of age. Babies younger than six months are a special population that require a different approach when it comes to fevers. Febrile babies require more investigation than their older counterparts.

Current HSE guidance would recommend medical attention be sought if:

  • Baby 0-3 months old develop a fever ≥38.0°C
  • Baby 3-6 months old develop a fever >39.0°C

This is recommended even if temperature is the only symptom present. This caution stems from a cautious approach and the baby’s inability to naturally fight some infections and incomplete vaccination status.

Vaccine-associated Temperatures:

Fever may occur in the first 48hrs after routine vaccine administration, and parents can be reassured that these particular fevers are normal in the absence of other concerning symptoms (Table 1).10 If a baby continued to have fevers beyond this timeframe, this would be abnormal and should be investigated further.

Temperature Management

There are numerous traditional methods of managing a fever, but the tried and tested means are:

  • Dress comfortably
  • Avoid fans/open windows or cold compresses
  • Treat aches or pains
  • Ensure the child is drinking plenty of fluids.

The instinct may be to strip clothes off and actively cool the patient, but this can cause shivering, and shivering can lead to an increase in temperature through movement. If the child is dressed comfortably, layers can be gradually removed if overheating. The importance of fluids cannot be understated. Dehydration compounds illness and has a detrimental effect on children. It is vital to anticipate this.

The most common first port of call for a temperature is an antipyretic such as paracetamol or ibuprofen. These are effective medications in reducing temperatures, though their use needs to be reasoned. As already discussed, the fact of having a temperature has little impact on the severity of the illness, and as such antipyretics play little part in improving the clinical condition. Whereas they are an effective means of improving the child’s comfort and wellbeing. Oftentimes, when we have a fever, we can be quite miserable, with aches and pains, and being somewhat off form. It is in these circumstances that antipyretics are endorsed. In the young >6month old children that lack the ability to convey their displeasure, this can be represented as excessive “crankiness”.

It is important to note:

  • Paracetamol should be given 4-6 hourly as required and never more than 4 times per day
  • Ibuprofen should be given 6-8 hourly as required and never more than 3 times per day.
  • Ibuprofen should be avoided in chickenpox unless clinician advised.
  • It is important to maintain adequate hydration in the setting of ibuprofen use. If a child is not maintaining full oral intake then ibuprofen use should be limited to 3 days.

Please note that HSE weight-based dosing guides for ibuprofen and paracetamol ( are derived from Irish College of General Practitioners General Practitioner Quick Reference Guide for Antipyretic Prescribing and are intended for use by prescribers only.11

Further Advice Supports

Finally, any time parents are in a medical setting with their child, it is often a time of high-stress and low-retention. One should be sure to provide written advice (e.g. digital resources) on the management and caveats of fevers, in order to allow the parent time to absorb the information or use it at their leisure. A broad sweep of expert advice for children 0-2 years is available from HSE resources.12 Other innovative methods such as infographics or short videos explaining the fever process have been proven to be of value and should be considered (Fig. 1).2 Also attached is an infographic advising the appropriate timeframes for returning to school/childcare after different infections/symptoms from the Health Protection Surveillance Centre (Fig. 2).13

Written by Karl Kavanagh1, Diarmaid Semple2, Michael Barrett1,3
  1. Department of Paediatric Emergency Medicine, Children’s Health Ireland at Crumlin, Dublin 12
  2. Pharmacy Department, Children’s Health Ireland at Crumlin, Dublin 12
  3. Women’s and Children’s Health, School of Medicine, University College Dublin

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