In developed countries children are immunised against serious illnesses, so these are less likely. A few questions are normally enough to reassure everybody.
Let's go through the checklist:
- How high was the temperature?
Sometimes people don't check the temperature, but think they have a fever as they feel hot. Actually, when the temperature is rising we tend to feel cold and shivery. This is a more reliable sign of a temperature than feeling hot. But having a working thermometer at home is a good idea. Ear thermometers are the most reliable ones. The temperature is considered high if it is above 38.5, below that, a serious acute illness is less likely.
- How long?
Temperature related to innocent infections, like respiratory viruses or tummy bugs, resolve within 5 days. Temperature is the first symptom to resolve during the recovery period. So any temperature lasting for longer than 5 days needs medical attention.
- How is the patient in general?
If the patient is generally well, tolerating fluids, passing urine, can continue with some of their daily activities, or the child perks up from time to time we are less worried. If they are constantly unwell, or deteriorating, it is a red flag, and needs urgent medical attention.
- What is the source of the infection?
If the patient has signs of cough, sore throat, runny and blocked nose, flu like symptoms, it is likely to be a respiratory tract infection, so we ask all the safety questions, like chest pain, breathlessness. If nothing worrying, we all can be reassured that it is a virus and will go on its own.
If the patient has stomach or urine issues we go down that route and check if medical intervention is needed.
But when we don’t find any apparent sources of infection, we really want to see the patient for physical examination and further testing to find the source.
In children who have temperature and feeling tired, unwell but nothing specific, the most common finding on examination will be tonsillitis. If the throat is clear we check the ears, the chest, the stomach, the skin for any rashes and do a urine dip test. We worry about a hidden infection that can be serious like a kidney infection or meningitis.
- Is the patient in the high risk groups?
Babies under the age of 3 months
always need to be seen urgently with a history of recorded high temperature due to the possibility of the rare but serious blood infection, called neonatal sepsis.
Unvaccinated children (and adults!)
might acquire serious infections that need intervention.
The elderly.
It is always a concern if an elderly person has high temperature, it always warrants medical assessment straight away and it is not safe to wait for the temperature to resolve on its own.
With underlying conditions.
Those who have severe underlying conditions like lung, kidney, liver or heart disease or their immune system is suppressed by their illness or by medication needs to speak to seek medical attention if they develop temperature.
It is almost like a reflex to take paracetamol or to give calpol to a child if we notice high temperature. This practice has been reinforced by doctors and nurses for years, however NICE guidance suggests:
Do not use antipyretic agents with the sole aim of reducing body temperature in children with fever.
But to give it only if the temperature is high, above 38.5, AND the child is distressed. So if the child is sleeping soundly, please don’t wake her up just to give the next dose of Calpol as it is due.
High temperature on its own, if it is not caused by a serious illness, will not harm your child. Some children can have febrile convulsions when they have a temperature, but giving Calpol or Nurofen will not prevent it from happening.
Paracetamol does provide symptom relief in half of the cases, it is safe and not known to prolong the fever duration.
Paracetamol or ibuprofen?
I would say that the first choice of most patients would be paracetamol when it comes to temperature relief, but some patients swear that only ibuprofen brings down their or their child’s temperature.
There is mixed advice out there, whether you can give/take one or the other or both together or alternating. There is some evidence that the measured temperature might be lower with the two medicines given together or alternating, however it did not really make the patient feel better.
Temperature is an immune response. So far we looked at the immune response to infections. Vaccinations also trigger an immune response that might manifest in high temperatures. Some vaccines, like the pneumococcal vaccine, tend to cause high temperatures more than other vaccines. Therefore it is common to advise to give the child paracetamol before or immediately after the jab. It was found that paracetamol reduced the immune response to the jab, however it still remains effective, especially after a booster dose. Ibuprofen however is not known to interfere with the immune response, so you might choose it over paracetamol in this instance.
https://www.nice.org.uk/donotdo/do-not-use-antipyretic-agents-with-the-sole-aim-of-reducing-body-temperaturein-children-with-fever
https://www.nice.org.uk/donotdo/antipyretic-agents-do-not-prevent-febrile-convulsions-and-should-not-be-usedspecifically-for-this-purpose
https://pubmed.ncbi.nlm.nih.gov/18175843/
https://pubmed.ncbi.nlm.nih.gov/25236309/
https://pubmed.ncbi.nlm.nih.gov/33894782/