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Causes of high fever in toddlers: Causes of High Fever in Children and When to Worry

High temperature (fever) in children

A high temperature (fever) is very common in young children. The temperature usually returns to normal within 3 or 4 days.

Checking a high temperature

A normal temperature in babies and children is about 36.4C, but this can vary slightly from child to child.

A high temperature is 38C or more.

If your child has a high temperature, they might:

  • feel hotter than usual when you touch their back or chest
  • feel sweaty
  • look or feel unwell

Use a digital thermometer, which you can buy from pharmacies and supermarkets, to take your child’s temperature.

How to take your child’s temperature

  1. Place the thermometer inside the top of the armpit.
  2. Gently close the arm over the thermometer and keep it pressed to the side of the body.
  3. Leave the thermometer in place for as long as it says in the instruction leaflet. Some digital thermometers beep when they’re ready.
  4. Remove the thermometer. The display will show your child’s temperature.

If your child’s just had a bath or been wrapped in a blanket, their temperature may be higher for a short time. Wait a few minutes then try again.

What to do if your child has a high temperature

If your child or baby has a high temperature, you can usually look after them at home. The temperature should go down over 3 or 4 days.

Do

  • give them plenty of fluids

  • look out for signs of dehydration

  • give them food if they want it

  • check on your child regularly during the night

  • keep them at home

  • give them paracetamol or ibuprofen if they’re distressed or unwell – check the packaging or leaflet to make sure the medicine is suitable for your child, or speak to a pharmacist or GP if you’re not sure

  • get medical advice if you’re worried about your child

Don’t

  • do not undress your child or sponge them down to cool them – a high temperature is a natural and healthy response to infection

  • do not cover them up in too many clothes or bedclothes

  • do not give aspirin to children under 16 years of age

  • do not combine ibuprofen and paracetamol, unless a GP tells you to

  • do not give paracetamol to a child under 2 months

  • do not give ibuprofen to a child under 3 months or under 5kg

  • do not give ibuprofen to children with asthma unless it’s been recommended by a doctor

Read more about giving medicines to babies and children

Urgent advice: Call 111 or your GP surgery now if your child:

  • is under 3 months old and has a temperature of 38C or higher, or you think they have a high temperature
  • is 3 to 6 months old and has a temperature of 39C or higher, or you think they have a high temperature
  • has other signs of illness, such as a rash, as well as a high temperature
  • has a high temperature that’s lasted for 5 days or more
  • does not want to eat, or is not their usual self and you’re worried
  • has a high temperature that does not come down with paracetamol
  • is dehydrated – such as nappies that are not very wet, sunken eyes, and no tears when they’re crying

Immediate action required: Call 999 if your child:

  • has a stiff neck
  • has a rash that does not fade when you press a glass against it
  • is bothered by light
  • has a fit (febrile seizure) for the first time (they cannot stop shaking)
  • has unusually cold hands and feet
  • has blue, pale or blotchy skin, lips or tongue
  • has a weak, high-pitched cry that’s not like their normal cry
  • is drowsy and hard to wake
  • is extremely agitated (does not stop crying) or is confused
  • finds it hard to breathe and sucks their stomach in under their ribs
  • is not responding like they normally do, or is not interested in feeding or normal activities

Causes of a high temperature in children

A high temperature is the body’s natural response to fighting infections like coughs and colds.

Many things can cause a high temperature in children, from common childhood illnesses like chickenpox and tonsillitis, to vaccinations.

Video: Caring for children with fever at home

Watch this video on how to help a child with fever recover as quickly as possible.

Media last reviewed: 1 June 2023
Media review due: 1 June 2026

Page last reviewed: 21 December 2020
Next review due: 21 December 2023

Fever in Children | Johns Hopkins Medicine

What is a fever?

A fever is defined by most healthcare provider as a temperature of 100.4°F (38°C) and higher when taken rectally.

The body has several ways to maintain normal body temperature. The organs involved in helping with temperature regulation include the brain, skin, muscle, and blood vessels. The body responds to changes in temperature by:

  • Increasing or decreasing sweat production.

  • Moving blood away from, or closer to, the surface of the skin.

  • Getting rid of, or holding on to, water in the body.

  • Seeking a cooler or warmer environment.

When your child has a fever, the body works the same way to control the temperature, but it has temporarily reset its thermostat at a higher temperature. The temperature increases for a number of reasons:

  • Chemicals, called cytokines and mediators, are made in the body in response to an invasion from a microorganism, malignancy, or other intruder.

  • The body is making more macrophages, which are cells that go to combat when intruders are present in the body. These cells actually “eat-up” the invading organism.

  • The body is busily trying to make natural antibodies, which fight infection. These antibodies will recognize the infection next time it tries to invade.

  • Many bacteria are enclosed in an overcoat-like membrane. When this membrane is disrupted or broken, the contents that escape can be toxic to the body and stimulate the brain to raise the temperature.

What conditions can cause a fever?

The following conditions can cause a fever:

  • Infectious diseases

  • Certain medicines

  • Heat stroke

  • Blood transfusion

  • Disorders in the brain

  • Some kinds of cancer

  • Some autoimmune diseases

What are the benefits of a fever?

Fever is not an illness. It is a symptom, or sign that your body is fighting an illness or infection. Fever stimulates the body’s defenses, sending white blood cells and other “fighter” cells to fight and destroy the cause of the infection.

What are the symptoms that my child may have a fever?

Children with fevers may become more uncomfortable as the temperature rises. In addition to a body temperature greater than 100.4°F (38°C), symptoms may include:

  • Your child may not be as active or talkative as usual.

  • He or she may seem fussier, less hungry, and thirstier.

  • Your child may feel warm or hot. Remember that even if your child feels like he or she is “burning up,” the measured temperature may not be that high.

The symptoms of a fever may look like other medical conditions. According to the American Academy of Pediatrics, if your child is younger than 3 months of age and has a temperature of 100.4°F (38°C) or higher, you should call your child’s healthcare provider immediately. If you are unsure, always check with your child’s healthcare provider for a diagnosis.

When should a fever be treated?

In children, a fever that is making them uncomfortable should be treated. Treating your child’s fever will not help the body get rid of the infection any faster; it simply will relieve discomfort associated with fever.  Children between the ages of 6 months and 5 years can develop seizures from fever (called febrile seizures). If your child does have a febrile seizure, there is a chance that the seizure may occur again, but, usually, children outgrow the febrile seizures. A febrile seizure does not mean your child has epilepsy. There is no evidence that treating the fever will reduce the risk of having a febrile seizure.

What can I do to decrease my child’s fever?

Give your child an antifever medicine, such as acetaminophen or ibuprofen. DO NOT give your child aspirin, as it has been linked to a serious, potentially fatal disease, called Reye syndrome.

Other ways to reduce a fever:

  • Dress your child lightly. Excess clothing will trap body heat and cause the temperature to rise.

  • Encourage your child to drink plenty of fluids, such as juices, soda, punch, or popsicles.

  • Give your child a lukewarm bath. Do not allow your child to shiver from cold water, as this can raise the body temperature. NEVER leave your child unattended in the bathtub. 

  • DO NOT use alcohol baths.

When should I call my child’s healthcare provider?

Unless advised otherwise by your child’s healthcare provider, call the provider right away if:

  • Your child is 3 months old or younger and has a fever of 100.4°F (38°C) or higher. Get medical care right away. Fever in a young baby can be a sign of a dangerous infection.

  • Your child is of any age and has repeated fevers above 104°F (40°C).

  • Your child is younger than 2 years of age and a fever of 100.4°F (38°C) continues for more than 1 day.

  • Your child is 2 years old or older and a fever of 100.4°F (38°C) continues for more than 3 days.

  • Your baby is fussy or cries and cannot be soothed.

reasons, recommendations of doctors of the Central Medical Clinic CMD Perovo, st. Novogireevskaya

An increase in body temperature in a child is the most common reason for seeking emergency medical care. And of course, it is right when the child’s parents, not self-medicating, seek medical help when their child has a fever.

However, it is useful for all parents to know some of the main causes of fever (fever) in a child and ways to normalize it.

Fever is divided into three main degrees of severity:

  • A – fever from 37.0 to 37.9 degrees – mild or subfebrile fever, subfebrile condition;
  • B – temperature increase from 38.0 to 39.0 degrees C – moderate fever;
  • B – from 39.0 to 41.0 – high fever;
  • D – increase in body temperature above 41 degrees – excessive (life-threatening) fever.

Fever in an infant

The body temperature of a newborn child during the first 5 – 7 days of life fluctuates around 37. 0, and in some children, an increase in body temperature during this period up to 38.0 – 39.0 is possible. This phenomenon is called transient hyperthermia of the newborn. In addition to hyperthermia, newborns are even more likely to have hypothermia, that is, a decrease in body temperature below normal. Due to the immaturity of the brain structures, not only newborn children, but also children of the younger age group up to 3-5 years old have a tendency to overheat quickly and to quickly hypothermia. Especially such a “volatility” of body temperature is typical, of course, for children in the first year of life. Therefore, if you, having measured the body temperature of a baby, found an increase in body temperature to 37.0 – 37.4 degrees, do not rush to immediately call a pediatrician. It is enough to measure the body temperature, having previously unswaddled the child, or simply remove a warm blanket from him so that after 15-20 minutes the temperature returns to normal.

Another common cause of an increase in body temperature in the first 1. 5 – 2 years of a child’s life is a reaction to teething. We wrote about this problem in a separate article on our website. In a nutshell, let me remind you that the reaction to teething in children is very individual. An increase in body temperature, most often, fits into the range from 37.1 to 37.6 degrees. Elevated temperature during teething usually lasts no more than 2-3 days, and in most children does not require the use of antipyretic drugs. However, in some cases, when teething, the child may have a fairly high fever of up to 38.0 and even up to 39.0 degrees. In this case, you can not do without the use of special anti-inflammatory gels for application to the gums and antipyretics in the form of suppositories (candles), such as Nurofen.

Prolonged, subfebrile fever in a child

If in infants the cause of sudden “temperature jumps”, most often, is the immaturity of the nervous system and the reaction to teething, then in older children, often prolonged subfebrile body temperature is kept against the background of psycho-emotional experiences, academic failure, conflict situations in the family. A separate problem is the active introduction of various electronic gadgets into the lives of modern children, sometimes from a very early age. So, for a child from 4 to 6 years old, who is already used to spending several hours a day at a computer or a game console, prolonged subfebrile condition can generally become commonplace, and parents, when they grab their heads from the thermometer readings, drag their child to neurologists , immunologists and infectious disease specialists, passing a bunch of tests, instead of just finding something more useful and healthy for the child.

Fever in children – NCCH

36.6˚ is the average normal body temperature for an adult. In children, the average body temperature is 0.3-0.4˚ C higher than in adults. In addition, the temperature in children is characterized by significant lability and its average fluctuations in newborns can be about 0.4 ° C, and in older children up to 1 ° C. Factors such as food intake, hunger, movement, restlessness, alternation of sleep and wakefulness. It must be remembered that there are daily fluctuations in temperature, in the evening it is usually slightly higher. In young children with insufficient maturity of thermoregulation processes, environmental factors have a significant impact, it is important to remember that children are very easy to both overcool and overheat, so the air temperature in the room, the quantity and quality of clothes on the child, etc. are important. If the child seemed hot to you, and you decided to measure the temperature, you must wait 15-20 minutes after sleep or physical activity, uncover the child. The temperature should not be measured in the hands of the mother, but in a calmly sitting or lying child. When measuring the temperature in the armpit, you just need to hold the child’s hand with a thermometer with your hand or use an ear infrared thermometer.

Fever is an increase in body temperature ≥38˚ C, in most cases it is not dangerous, it is a normal physiological reaction of the body to infectious and non-infectious diseases. In young children, febrile illnesses are common and are usually caused by viral infections.

In the body, the role of the thermoregulation center is performed by the hypothalamus, the mechanism of its action is based on achieving a balance between heat production and heat loss.

Febrile convulsions are genetically determined, develop in 3-4% of children, as a rule, are not accompanied by epileptic activity of the brain, do not affect the further development of the child and do not recur after 6 years. In almost 50% of cases, febrile convulsions are single, however, if they are present in the history of the child, antipyretics are recommended for him at lower fever numbers.

Of course, one can understand the excitement of parents and grandparents when a child has a fever, but they need to remember that by lowering the temperature, especially low values, they calm themselves more than help the child. So, in most viral infections, only during an increase in temperature, antibodies to the virus and various active substances are produced that are responsible for the immune response and immunological memory. Therefore, an artificial decrease in temperature can lengthen the period of the disease. If a child has started antibiotic therapy for a bacterial infection, it is important to evaluate the effectiveness of the antibiotic, which can be seen primarily by self-reduction of body temperature. Against the background of antipyretics, this is quite difficult to do, and the sooner the child receives the correct treatment, the lower the risk of possible complications. Taking into account all of the above, international recommendations have been developed for the appointment of antipyretics. They are indicated in initially healthy children under the age of 3 months with an increase in body temperature above 38 °C. For children older than 3 months, antipyretics are prescribed at a temperature above 39-39.5˚С. For children at risk (with congenital heart defects, diseases of the central nervous system, etc.), as well as with previously identified febrile convulsions, the temperature is reduced to a lower temperature – 37. 5-38 ° C. If the child feels unwell with a fever, refuses to eat and drink, parents can begin to lower the temperature to a lower temperature. No guideline for the management of children with fever recommends the use of antipyretics solely to reduce fever.

Temperature reduction is carried out by physical cooling methods and, if necessary, medication. If the child does not have chills, marbling of the skin, the room should be ventilated, the child is open. With cold hands and feet, they must be rubbed to redness or given a no-shpu in order to expand the peripheral vessels for an adequate heat transfer process. The drugs of choice among antipyretics for children are paracetamol and ibuprofen with many convenient dosage forms for the child. A single dose is calculated on body weight and is 10-15 mg / kg (every 6 hours, if necessary) for paracetamol and 5-10 mg / kg (every 6 hours, if necessary) for ibuprofen. If the dose of antipyretics is insufficient, the effect of them may not be. In the presence of vomiting, the form in candles is convenient. A decrease in temperature, as a rule, can be expected 30-60 minutes after taking the drug (somewhat longer with rectal use) and the effect lasts up to 3-8 hours. If the temperature is very high, physical cooling methods can be used until the antipyretic begins to take effect or until the time of the next dose of the drug. Vinegar and vodka, when rubbed, can have both a local irritant effect and a toxic effect when absorbed through the skin. Therefore, the simplest and safest way is to wipe the child with ordinary water at 25-30˚ C. It is necessary to wipe the neck, back of the head, inguinal and axillary folds, forehead, and then other surfaces.

It is not recommended to alternate paracetamol and ibuprofen, as well as to give their combined preparations, this combination is no more effective than monotherapy, but is fraught with serious side effects and can lead to acute renal failure. Also, nimesulide, acetylsalicylic acid preparations are not used in children with an antipyretic purpose, and metamizole (analgin) can only be administered intramuscularly in order to quickly reduce the temperature. All of these drugs can cause serious side effects that are incomparable to their antipyretic effect.

Usually a decrease in temperature by 0.5-1˚ C is sufficient to improve the child’s well-being, it is not necessary to achieve a decrease in temperature to normal numbers. Large diurnal fluctuations in temperature may have a more significant negative effect than the fever itself.

We have already said above that fever in children is most often accompanied by acute infectious diseases, which can be of both viral and bacterial etiology. In the vast majority of cases, a viral infection does not require the appointment of an antibiotic (antibiotics do not act on viruses), children are treated with symptomatic agents and, if necessary, reduce the temperature. In the case of a proven bacterial etiology of the disease, it is necessary to prescribe antibiotic therapy. It is up to the doctor to decide what exactly the child is sick with, and, accordingly, how to treat him. However, if the disease begins with fever, runny nose and cough, the child’s condition suffers slightly, with a high degree of probability one can think about the development of a respiratory viral infection and treat the child symptomatically.