Fever in Children: Look at the Child, Not the Thermometer

Fever is the symptom that worries families most in childhood and the most common reason for consulting a doctor. Yet fever is not an illness in itself but a natural and usually beneficial response of the body to an infection; when the temperature rises the immune system works more effectively and it becomes harder for germs to multiply. The mistake families make most often is to think that the number on the thermometer shows the severity of the illness; in reality a child playing with a temperature of 38.5 degrees is far less worrying than a child lying listless and unresponsive at 37.8 degrees. For this reason the assessment should place at its centre not the reading but the child's general condition, fluid intake, breathing and level of consciousness. Age is also decisive: in babies under three months, fever is always a priority finding in its own right. In this article we look at why fever occurs, how to measure it correctly, what should and should not be done at home, which findings allow no delay, and what needs to be known about febrile seizures.

What Is Fever and Why Does It Occur?

Body temperature is kept within a certain range, much like a thermostat, by a centre in the region of the brain called the hypothalamus. During an infection, substances released by the immune system raise this centre's target temperature; because the body now accepts a higher value as "normal", the person feels cold, shivers and wants to cover up. The shivering, feeling cold and cold hands and feet seen while the fever is rising should therefore be regarded as natural; sweating, on the other hand, is usually a sign that the temperature has begun to fall. The most common cause of fever in children is viral infection, which accounts for the great majority of cases: colds, influenza, throat and intestinal infections fall into this group and do not require antibiotics. In a smaller proportion there are bacterial causes such as middle ear infection, urinary tract infection or pneumonia, and these are distinguished by medical assessment. There are also non-infectious causes, chief among them fluid loss, overdressing, staying in a very hot environment, mild rises lasting a day after vaccination, and rheumatological diseases. Teething may cause a slight increase in body temperature; however, attributing a high fever to teething is a common mistake that causes an underlying infection to be missed.

How Is Fever Measured?

Assessing fever correctly depends first on measuring it correctly; checking by placing a hand on the forehead is not reliable and can lead both to unnecessary panic and to dangerous delay. Threshold values vary according to where the measurement is taken: in general, values above about 37.2 degrees in the armpit, 37.8 degrees in ear and forehead measurements, and 38 degrees rectally are accepted as fever. Mercury glass thermometers are no longer recommended because of the risk of breakage and poisoning; digital thermometers are both safer and more practical. The method should be chosen according to age group: armpit measurement is safe and easy in small babies, ear measurement is suitable in children over about six months, and oral measurement is meaningful only in children old enough to hold the thermometer properly under the tongue. There are also situations that spoil the accuracy of the measurement: the reading will be misleading in a child who has just come out of the bath, is heavily dressed, is swaddled or is sweating, so half an hour should be allowed to pass. Rather than comparing values taken by different methods, it is far more useful for follow-up to measure with the same method and to note the time of the reading. Taking the temperature every minute makes the child restless; measuring when there is a change in general condition, or about an hour after medication has been given, is enough.

What Should Be Done at Home?

The aim of what is done at home for a feverish child is not to bring the thermometer down to a particular number but to make the child comfortable and maintain fluid balance. The first step is to remove thick clothing, leave the child in light cotton clothes and cover them with a thin sheet; dressing in layers and wrapping in a quilt prevents heat loss and pushes the fever higher still. The room temperature should be kept neither too hot nor too cold, at around twenty-one to twenty-four degrees, and the room should be ventilated regularly. Because fever causes fluid loss by increasing sweating and the breathing rate, plenty of fluids must be given; breastfed babies should be fed more frequently, and older children should be offered water, soup and suitable fluids. If the temperature remains high and the child is restless, sponging with lukewarm water or a short lukewarm shower may be soothing; the water should feel lukewarm to the back of the hand, and the procedure should be stopped if the child begins to shiver. There is no need to insist on eating; loss of appetite is expected during a feverish period, and what matters is that fluid intake continues. Letting the child rest rather than run and jump, and allowing them to sleep when they want to, supports the recovery process.

Fever-Reducing Medicine: When and How?

The purpose of fever-reducing medicines is not to eliminate the fever entirely but to relieve the child's discomfort; these medicines do not change the course of the infection and do not speed up recovery. The basic question should therefore not be "how many degrees is the fever" but "is my child feverish but well, or feverish and distressed?" There is no need to hurry to give medicine to a child who is still playing, able to take fluids and free of pain; by contrast, medicine should be given if the child is restless, in pain, unable to sleep or having difficulty taking fluids. The fever-reducing medicines used in children contain the active substances paracetamol and ibuprofen; which one is suitable, and its dose and interval, should be determined by a physician according to the child's age, weight and existing conditions. The dose must always be given with the medicine's own measuring device; variable measures such as teaspoons or tablespoons should not be used. Medicines containing aspirin, that is acetylsalicylic acid, must never be used as fever reducers in children; they can lead to a severe condition affecting the liver and brain known as Reye's syndrome. Alternating two different fever reducers is a widespread practice, but it has not been shown to offer a clear advantage over a single medicine and increases the risk of dosing confusion; it should therefore be done only when a physician recommends it.

What Must Never Be Done at Home

Some traditional practices carried out to bring down fever are not merely ineffective but directly harmful. Foremost among them is wiping the child's body with alcohol, cologne or vinegar; these substances can be absorbed through a child's thin skin and cause poisoning, and the vapour inhaled is also distressing. The second common mistake is bathing the child in cold or iced water or wrapping them in a wet, cold towel; this constricts the blood vessels, makes it harder for heat to be released, and causes shivering and a renewed rise in temperature, sometimes with a dangerous drop in body heat. Dressing the child warmly and wrapping them in a blanket because they say they feel cold is likewise a frequent error that pushes the fever higher. Starting leftover antibiotics from home without a medical examination, or pressing a physician to prescribe antibiotics, leads both to unnecessary medication and to the development of resistance; the most common cause of fever in children is viruses in any case. Giving fever-reducing medicine at shorter intervals than recommended, one after another or at a high dose, is likewise dangerous and can cause serious side effects on the liver and kidneys. Finally, stopping treatment or not attending a follow-up because the fever has come down is not correct; a fall in temperature does not mean the underlying illness has resolved.

What Needs to Be Known About Febrile Seizures

A febrile seizure, known in medicine as a febrile convulsion, is a condition that may be seen in children between six months and five years of age and is the one families fear most. During a seizure the child's body stiffens and relaxes, the eyes roll upward or fix on a point, contact with the surroundings is lost, saliva may come from the mouth, and brief blueness and loss of bladder control may be seen. Although it looks extremely frightening, the great majority of simple febrile seizures end by themselves within a few minutes and leave no lasting harm in the child; contrary to what is supposed, this condition does not lead to epilepsy, intellectual disability or disability. What needs to be done during a seizure is simple: the child should be laid on a soft, safe surface, preferably on their side, hard objects around them should be moved away, and the time the seizure started should be noted. Nothing whatsoever should be put in their mouth, no attempt should be made to hold the tongue, no water should be given, and no attempt should be made to force the stiffening arms and legs to stop; such attempts can cause injury and choking. If the seizure lasts longer than five minutes, recurs one after another, the child does not come round afterwards, or this is their first seizure, emergency medical help should be called without delay. There is one more important point to know here: giving fever-reducing medicine regularly does not prevent febrile seizures; medicine should therefore be used to make the child comfortable, not out of fear of a seizure.

When Should a Doctor Be Consulted Without Delay?

Not every feverish child needs to be rushed to the emergency department; but some situations allow no waiting, and knowing this list is a family's greatest support. In babies under three months, every temperature of 38 degrees or above must be assessed without delay, even in the absence of any other finding; in the newborn period this may require monitoring in hospital. Whatever the source of the fever, a child appearing drowsy, unresponsive or excessively sleepy, moaning continuously or crying without stopping, are important warning signs. Shortness of breath, rapid and laboured breathing, blueness of the lips or skin, neck stiffness, severe headache, persistent vomiting and inability to take fluids also require emergency assessment. Rashes appearing together with fever should be examined carefully, and if there are small red-purple spots that do not fade when pressed, a healthcare facility should be attended at once. Dryness of the mouth, absence of tears when crying, a sunken or bulging fontanelle in babies, and a marked decrease in the amount of urine are signs of fluid loss. Fever lasting longer than three days, not coming down at all despite fever-reducing medicine or rising again quickly, a previous seizure, and the presence of heart, lung, metabolic or immune conditions are also situations requiring medical assessment.

Frequently Asked Questions

Does a high fever cause brain damage? Fever due to infection rises under the body's own control mechanism, so it generally does not exceed a certain limit and does not by itself cause brain damage. The real risk comes not from the fever but from the underlying illness; in conditions such as meningitis it is the infection itself that causes harm. By contrast, externally caused overheating such as heatstroke is assessed differently and is an emergency. For this reason the focus should be on the child's general condition rather than the number on the thermometer.

My child's fever has come down — does that mean they have recovered? No. Fever-reducing medicine only lowers the temperature temporarily; it does not treat the infection, and the fever may rise again when the medicine wears off. This does not mean the illness has worsened; it shows that the illness is still present. The sign of recovery is the child becoming progressively more lively and hungry during the periods without fever.

Does teething cause a high fever? Teething may cause a slight rise in body temperature, but it is not accepted as a cause of marked high fever. A high fever appearing during this period usually has a concurrent infection behind it. Automatically attributing fever to teeth may cause conditions such as middle ear infection or urinary tract infection to be missed. For this reason an examination is needed for a high fever even during teething.

Is fever after vaccination normal? Mild fever lasting about a day after vaccination, and redness at the injection site, are expected findings showing that the immune system is responding. Plenty of fluids and light clothing are usually enough in this period; if the child is restless, the fever reducer recommended by the physician may be used. However, assessment is needed if the fever lasts longer than expected, runs very high, or the child's general condition deteriorates. In small babies, fever after vaccination is handled according to the same age rules.

Should I start antibiotics for a child with a fever? Antibiotics should not be started without a medical examination and assessment. The great majority of fevers in children are viral in origin, and antibiotics are of no benefit at all in these infections. Unnecessary use leads, alongside side effects, to the development of resistance that will make them ineffective in a genuine infection later on. If a bacterial cause is identified, the appropriate medicine and duration are determined by the physician.

This article has been prepared for general information purposes only and does not take the place of a medical examination. If your child has fever together with deterioration in general condition, difficulty breathing, a rash, a seizure or an inability to take fluids, please attend a healthcare facility without delay.