Fever in a child

My child has a fever – should I be worried?

Caring for an ill child can be a very daunting experience for parents and carers, especially if you are not from a medical background. Hopefully, by the end of this post, you should be better informed and have a clearer idea of what to look out for in a child over 6 months old (signs can be very different in younger children). 

First of all, a fever (temperature above 38℃) is a healthy response to help fight infections so a fever alone is not concerning and will not harm your child. However, there are certain features that can help guide some diagnoses. 

It’s also important to note that MOST children with fever will get better within 5 days and will not get better with antibiotics, as they are caused by viruses. 

In cases that seem out of the ordinary there are ways to figure out how serious it could be…

A system that doctors use for assessing how serious a fever can be is the Traffic light system (NICE clinical guidelines, 2019). It looks complicated but will seem like common sense and become easier to read if we think about the first column first:

  • Colour – risk increases as the lips or tongue change colour (white/grey/blue)
  • Activity – risk increases if the child moves less than usual (this might be very clear if your child is usually very energetic)
  • Respiration (breathing) – risk increases if they are struggling to breathe (using their body or muscles to breathe in/out) or breathing faster than usual (‘tachypnoea’)

NOTE: The number of breaths to be worried for will depend on the age and is best assessed by your doctor.

Circulation and hydration – risk increases if their heart rate is a lot faster than usual, if they’re mouth is dry, if they are feeding 50% less than usual (infants: less than 1 year old), if their nappy is drier than usual or if they are peeing less than usual.

NOTE: Again…The heart rate, ‘CRT’ (Capillary Refill Time) and Urine output will depend on the age and is best assessed by your doctor.

OTHERS (‘Red flags’):

  • Duration of fever – you should call the doctor immediately if the fever has been going on for 5 days or more. This can be a sign of a more serious infection. 
  • In infants (less than 12 months) a worrying temperature depends:
    • Aged 3-6 months → temperature ≥ 39℃ 
    • Aged less than 3 months → temperature ≥ 38℃ (i.e. ANY fever in a child less than 3 months is worrying).
  • ANY of these signs need medical attention:
    • Swelling of the arms/legs/joints
    • ‘Non-blanching rash’ (see below)
    • Neck stiffness 
    • Seizures (shaking uncontrollably)
    • Difficulty in moving or feeling a part of their body
    • If they’re unconscious 
    • Bulging fontanelle (the open part of the head in infants)

What is a ‘non-blanching rash’ and what does it mean?

Meningitis is a serious and potentially life-threatening condition. 

A tell-tale sign of this serious infection is a ‘non-blanching rash’ accompanied by a fever and/or neck stiffness. 

The doctor will want to rule this out and an easy way to do this is through the ‘glass test’: rolling a transparent glass over the rash (see image; right). If the rash doesn’t disappear then it is ‘non-blanching’, and will need an admission to A&E as soon as possible.

Thankfully, meningitis is rarer now because of the routine vaccinations that your child will receive over the next few months and years [3]


Taking care of a child with fever is a scary experience for any parent or carer but there are some clear signs for you to look out for. It should be reassuring to know that the vast majority of fever in children are normal, treated best conservatively (e.g. Paracetamol and/or Ibuprofen, a healthy diet and plenty of water). If you are worried always consult your doctor for clarification. For more information and advice please feel free to book an appointment with one of our GPs by either visiting our website or call us on 0203 371 0995. This article is not intended to be medical advice!


[1] https://www.nice.org.uk/guidance/ng143/resources/support-for-education-and-learning-educational-resource-traffic-light-table-pdf-6960664333 

[2] https://journals.sagepub.com/doi/abs/10.1093/innovait/inq070?journalCode=inoa (rash image)

[3] https://www.nhs.uk/conditions/meningitis/

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