What can cause a high fever in a 1-year-old child. How to properly take a rectal temperature. Symptoms, treatments, and when to consult a doctor for fever in infants.

Understanding Fever in Babies

Fever in babies is a common concern that can cause worry among parents and caregivers. However, it is important to understand that fever is often a sign of a healthy immune system fighting off an infection. While a fever can be concerning, especially in newborns, it is generally not a serious condition on its own.

What Is Fever in Babies?

A typical temperature in a child under the age of 12 months is an average of 98.6°F (37°C) when using a rectal thermometer. This temperature can range from as low as 96.8°F (36°C) in the morning to as high as 100.3°F (37.9°C) later in the day, which is considered a normal range for an infant.

Fever in a child is defined as:

• Above 100.4°F (38°C) using a rectal thermometer
• Above 100°F (37.8°C) using an oral thermometer (not accurate in infants)
• Above 99°F (37.2°C) using an armpit thermometer

What Does Fever Mean?

By itself, a fever does not necessarily signal a serious illness. If the baby is behaving as they normally would, they are likely to be fine. However, if a baby under 3 months of age has a rectal temperature of 100.4°F (38°C) or higher, a parent or caregiver should call a doctor immediately.

The severity of a fever does not always indicate how unwell a child is at the time. Babies’ body temperatures can rise for many reasons other than illness, such as extended crying, sitting in the hot sun, or teething. Their bodies are also less able to regulate temperature than an adult’s, making it more difficult for them to cool down during a fever.

Causes of Fever in Babies

Fever is a symptom of an illness, not the illness itself. Fever occurs due to the immune system fighting against infections, which can be bacterial or viral. Common causes of fevers in babies include:

• Viral infections, such as the common cold, flu, roseola, or respiratory infections
• Ear infections
• Pneumonia (viral or bacterial)
• Meningitis (viral or bacterial)
• Urinary tract infections

Rarely, heat-related illnesses can also cause high temperatures in babies, as they are less effective at controlling their body temperature than adults.

When Should Parents Be Worried?

While fevers can be concerning, they are generally not serious, except in rare cases. Fevers of up to 105°F (40.5°C) are common in babies and children, and the fever itself is not dangerous. Instead, parents and caregivers should focus on monitoring the child for signs of complications or the underlying infection.

However, a doctor should examine babies younger than 3 months for any signs of fever, as certain infections are more common and can be more dangerous in newborns.

Fever Complications

Some parents or caregivers may hear about fevers leading to complications, such as seizures or brain damage. While these complications can occur in rare cases, they are not common. Fevers are generally not dangerous on their own, and the underlying infection is more likely to cause complications than the fever itself.

Instead, parents and caregivers should focus on managing the fever and monitoring the child for any signs of worsening symptoms or complications.

Caring for a Baby with a Fever

When caring for a baby with a fever, parents and caregivers should:

• Dress the baby in lightweight clothing
• Provide plenty of fluids to keep the baby hydrated
• Use over-the-counter fever-reducing medications as directed by a doctor
• Monitor the baby for any signs of worsening symptoms or complications
• Seek medical attention if the fever persists or the baby appears to be in distress

It is important to note that treating the fever will not make the underlying infection go away. The goal of fever management is to make the baby more comfortable and monitor for any signs of complications.

When to Seek Medical Advice

Parents and caregivers should seek medical attention if:

• The baby is under 3 months of age and has a fever of 100.4°F (38°C) or higher
• The fever persists for more than 24 hours in a baby under 2 years old
• The baby appears to be in distress or is exhibiting any concerning symptoms

In these cases, it is important to have the baby examined by a healthcare provider to rule out any serious underlying conditions and provide appropriate treatment.

Causes, treatments, and when to speak with a doctor

Fever in babies is a common concern that can cause worry among parents and caregivers. Understanding the temperature of fever in babies and what can cause fever can help with knowing how to care for the baby and when to seek medical advice.

A fever most often means that a baby’s body is fighting off an infection. Parents and caregivers may worry when they notice a baby has a fever, although this is a sign of a healthy immune system. However, because newborns have more vulnerable bodies, a fever can signal a serious infection.

This article examines the causes of fever in babies, what it means, and when a parent or caregiver may want to take the baby to a doctor. It also discusses how to care for a baby with a fever.

When taking a baby’s temperature, a rectal thermometer generally gives the most accurate results.

What is fever in babies?

A typical temperature in a child under the age of 12 months is an average of 98. 6°F (37°C) when using a rectal thermometer. In the morning, this temperature can be as low as 96.8°F (36°C) and go up to 100.3°F (37.9°C) later in the day. This is a normal range for an infant at this age.

Fever in a child depends on the method of taking the temperature:

• above 100.4°F (38°C) using a rectal thermometer
• above 100°F (37.8°C) using an oral thermometer, however, this method is not accurate in infants
• above 99°F (37.2°C) using an armpit thermometer

What does fever mean?

By itself, a fever does not necessarily signal a serious illness. If the baby is behaving as they would, they are likely to be fine. However, if a baby under 3 months of age has a rectal temperature of 100.4°F (38°C) or higher, a parent or caregiver should call a doctor.

Additionally, the severity of a fever does not always indicate how unwell a child is at the time. The body temperatures of babies can rise for many reasons other than illness, including extended crying, sitting in the hot sun, or spending time playing. Their temperature may also slightly rise when they are teething. None of these things causes a fever.

A baby’s body is also less able to regulate temperature than an adult body, meaning it can be more difficult for them to cool down during a fever. Their bodies are naturally warmer than an adult’s body because they are more metabolically active, which generates heat.

A fever is a symptom of an illness, not the illness itself. Fever occurs due to the immune system fighting against infections, which can be bacterial or viral. Viral infections are much more common.

Common causes of fevers in babies include:

• viral infections, including the common cold, the flu, roseola, or respiratory infections, such as respiratory syncytial virus or viral croup
• ear infections
• pneumonia, which can be viral or bacterial
• meningitis, which can be viral or bacterial and is a very serious infection of the brain and spinal cord
• A fever of 100.4°F (38°C) or higher before the age of 3 months. At this age, any bacterial infection can progress quickly and lead to sepsis, so an infant needs immediate medical care.
• A fever after a vaccine that can occur within 12 hours after the shot and lasts for 2–3 days.
• Rarely, heat-related illnesses can cause high temperatures in babies. Babies are less effective at controlling their body temperature than adults, making them more vulnerable to very hot weather. Dressing babies in weather-appropriate clothing, keeping them out of the hot sun, and keeping them indoors when the weather is very hot will help regulate their body temperature.
• urinary tract infection, a bacterial infection that can sometimes cause fever in babies

Despite common beliefs, teething does not cause a fever.

Fevers are a sign that the baby’s immune system is fighting infection, so the fever itself is not dangerous. What may put the baby at risk is the underlying infection, if it is serious.

Should parents be worried?

Some parents and caregivers may worry that fevers are dangerous. However, except in rare cases, these fevers themselves are rarely serious.

Fevers of up to 105°F (40.5°C) are common in babies and children whose temperatures often get much higher than an adult’s temperature. Where there is a viral infection causing this fever, they may just need to run their course. Some bacterial infections may require treatment with antibiotics, but the fever itself is just a symptom.

Additionally, treating the fever will not make the infection go away. Instead, parents and caregivers should simply carefully monitor the child for signs of complications.

However, a doctor needs to examine babies younger than 3 months for any signs of fever. This is to check for underlying conditions, as certain infections are more common and can be more dangerous in newborns.

Fever complications

Some parents or caregivers may hear about fevers causing brain damage. However, this can only happen if the temperature rises above 107°F (41.6°C), which is very rare. When an infant’s temperature is below this, there is no need to take drastic measures, such as ice baths, to lower the child’s fever.

For 2–5% of children aged between 6 months and 5 years, a fever can cause a seizure, which can be worrying but is not typically harmful. Doctors call them febrile seizures.

Febrile seizures do not cause brain damage or increase a child’s risk of epilepsy. Even long seizures, or those that last longer than 15 minutes, usually have a good outcome. However, prolonged seizures may mean a child is more likely to develop epilepsy.

The biggest risk of febrile seizures is that a child may fall, hit their head, or suffer a similar injury. Therefore, parents and caregivers should monitor children during a seizure to prevent injury and call 911 or emergency services for any seizures in a baby that continue for longer than 5 minutes.

The American Academy of Pediatrics (AAP) recommends that parents and caregivers make their babies comfortable if they have a fever, rather than focusing on lowering their temperature.

To look after a baby with a fever, parents and caregivers can:

• Monitor the baby’s activity level and overall comfort: Babies who seem happy, alert, and comfortable may not need treatment.
• Ensure the baby remains well hydrated: Fever increases the risk of dehydration, so parents, caregivers, and nurses should offer milk or formula on demand. Older babies should also drink plenty of water. In some cases, a healthcare professional may recommend using an electrolyte drink to help with dehydration.
• Monitor the baby for signs of dehydration: This can include not urinating as often as usual, sunken eyes, chapped lips, or very dry or pasty-looking skin.
• Avoid waking a sleeping baby to administer anti-fever medication: Unless a doctor instructs to do this.
• Administer anti-fever medication under a doctor’s supervision: People can give this medication if the infant is in pain or uncomfortable from the fever. The baby’s weight determines the dose, so follow the label instructions carefully. Call a doctor before giving new medication to a baby, especially a sick one.
• Help limit the spread of infections: Do not send a sick baby to daycare or take them to places where babies or other vulnerable people may be, as this can spread infections.

Call a doctor or seek medical care if a baby has a fever and one of the following:

• The baby is inconsolable, lethargic, or seems very sick.
• A fever lasts longer than 24 hours in a baby younger than 2 years old without other symptoms.
• The fever rises above 104°F (40°C).
• The child still seems sick with medication.
• The baby is taking antibiotics but does not seem better within a day or two.
• The baby has signs of dehydration, including dry lips or a sunken soft spot on top of their head.
• The baby has a weak immune system for a separate reason.
• The baby is younger than 3 months old.

Go to the emergency room for a fever if a baby:

• is a newborn
• has a seizure for the first time
• has a seizure that lasts longer than 15 minutes
• has a fever rising to 107°F (41.6°C) or higher

A fever in a newborn may be a sign of a serious medical condition. Newborns are more vulnerable to infections, so it is important to take any signs of infection seriously. Call a doctor if a newborn has a fever or other signs of illness.

One concern with newborns is respiratory illness. Newborns breathe more through their noses than older infants and children, so congestion can make breathing appear more difficult. They also have smaller airways.

A lack of oxygen can seriously injure a newborn. If a baby has trouble breathing, call a doctor, even if their fever goes down.

Signs that a newborn is having trouble breathing include:

• wheezing or grunting
• flaring the nostrils when breathing
• white or blue skin, especially around the nail beds or on the mouth or tongue, though this may be harder to detect in infants with darker skin.
• pulling in the muscles around the ribs when breathing

If a baby has breathing problems and a fever, a parent or caregiver should take them to the emergency room immediately.

Young children and babies sometimes experience fevers, but this is usually not a cause for concern when infants are behaving as expected.

Parents and carers can use a child’s behavior as a cue. If a baby seems fine but has a fever, the illness is probably a minor one that will soon pass.

Lethargy, excessive crying, and other signs of serious illness are important to address, even if a child’s fever is fairly low. A fever means that the immune system is working hard to fight an infection.

Parents and caregivers do not need to treat the fever itself, but they can comfort the baby and treat the symptoms instead. If they are unsure whether a baby’s symptoms are serious, they should consult with a healthcare professional.

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

If a child has a fever, what should I do?

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05/14/2019

Before you start taking antipyretics, you need to answer a few questions:

• what is the age of the child?

• How does a child tolerate an increase in a particular temperature?

• Have there been any family or child history of febrile seizures?

• Are there any other symptoms of the disease besides fever?

An increase in temperature or fever is a protective and adaptive reaction of the body in response to the effects of pathogenic stimuli, which results in a restructuring of thermoregulation processes, leading to an increase in body temperature, which stimulates the body’s natural resistance.

An increase in temperature affects the child’s body both positively and negatively.

The positive effect of is that when the temperature rises in the child’s body, the immune system is activated, phagocytosis increases, the production of antibodies increases and the level of interferon increases, which helps to stop the reproduction of pathogenic microorganisms and overcome the infection.

Negative influence high temperature in a child is manifested in the occurrence of convulsions (febrile), increased stress on the baby’s cardiopulmonary system (heart rate and respiratory rate become more frequent). Therefore, fever is dangerous for children with malformations of the heart and bronchopulmonary system, heart rhythm disturbance. Also, when the temperature rises, the work of the brain, liver, stomach, kidneys and other internal organs suffers, which is dangerous for children with chronic pathologies of internal organs, symptoms of dehydration, developmental disorders and diseases of the nervous system.

Fever varies:

1. with the flow:

   • acute (fever up to 2 weeks),

   • subacute (up to 6 weeks),

   • chronic (over 6 weeks).

2. by the degree of increase of the indicator:

   • subfebrile (increase to +38.0 degrees)

   • febrile (from +38.0 to +39.0 degrees),

   • pyretic (from + 39.0 to + 41.0 degrees),

   • hyperpyretic (over +41.0 degrees).

3. according to the type of temperature curve:

   • constant (temperature fluctuations during the day are not higher than 1 degree).

   • laxative (daily fluctuations up to 2 degrees),

   • atypical (fluctuations are chaotic, different and irregular),

   • debilitating (a combination of laxative and atypical fever with fluctuations during the day more than 2-3 degrees),

   • intermittent (a combination of short periods of temperature increase and decrease to normal numbers),

   • return (alternation of periods of temperature increase with periods of temperature normalization from 2 to 7 days).

On the recommendation of the WHO (World Health Organization), antipyretics are prescribed for children according to age:

• from the moment of birth to 2 months at a temperature of +38.0 degrees,

• children from 3 months to 24 months at a temperature of +38.5 degrees,

• children from 1 to 5 years old at a temperature of +39.0 degrees,

• children over 5 years old with indicators of + 39.5- + 40.0 degrees.

On the other hand, the approach to each child should be individual.

If a child

• restless or feeling weak,
• cannot tolerate muscle pain, headache,
• have nausea,
• no appetite,

then you must first apply physical methods to improve the well-being of the child :

• put to bed – so the body will save strength to fight the infection, calm the child;

• drink fractionally with water or sweetened warm herbal tea with chamomile, linden, cranberry juice;

• provide access to fresh air;

• to feed in the presence of appetite in small portions of warm food (for example, soup, liquid porridge on the water, a light breakfast).

Also, according to the clinical variant of the course of fever, apply additional cooling measures.

With “red” or “pink” fever

• the child’s body feels hot to the touch,
• skin red or pink, moist,
• the child himself does not complain about his well-being, he is active, his appetite does not disappear.

In this case, child needs

• undress,
• wipe with a towel soaked in water at room temperature,
• apply a cool compress to the forehead,
• drink water at room temperature
• and be sure to call a doctor.

With “white or pale” fever

• the limbs and body of the child are cold to the touch,
• lips and nail beds become bluish,
• pale and dry skin,
• there is a violation of well-being: the child is lethargic, delirium is possible.

In this case child needs

• warm by rubbing the limbs with hands or using warm water (no other means!),
• put on socks,
• cover with a blanket
• and drink warm tea or water.

The use of antipyretics for such symptoms is ineffective – you need to urgently call a doctor!

An exception is children at risk, who have their temperature reduced above 37.1 degrees. These are children,

• with diseases of the nervous system,
• convulsions due to fever,
• suffering from chronic diseases of the circulatory system, respiratory organs or with hereditary metabolic diseases and other risks (overheating, symptoms of dehydration, etc.).

Febrile convulsions are diagnosed more often in children under 6 years of age with temperatures above +38 degrees, as well as in children with pathology of the nervous system at any temperature. For such children, it is recommended to lower the temperature to febrile levels (not higher than +38.0) or to those values ​​recommended by a neuropathologist.

Usually, against the background of an increase in temperature, the child’s heart rate and respiratory rate increase: the respiratory rate increases by 4 respiratory movements for every degree above +37. 0 degrees, and the pulse rate – by 20 beats per minute for every degree. However, against the background of diseases of the cardiovascular system and respiratory organs, such as malformations or cardiac arrhythmias, inadequate increases or slowdowns in heart rate and respiration are possible. Such children, on the recommendation of a cardiologist and pulmonologist, are prescribed antipyretic drugs to febrile numbers (ie, not higher than +38.0 degrees).

Children with hereditary metabolic diseases (diseases of the thyroid gland, kidneys, liver, disorders in the immune system, and others) and children with imperfect compensatory mechanisms of thermoregulation during fever (these are some children from birth to 2 months) are also prescribed antipyretic drugs on the recommendation of related specialists means to febrile digits.

Overheating – increase in body temperature due to additional exposure to heat

• prolonged sun exposure,
• use of excess clothing,
• excessive wrapping of children).

The danger of overheating is associated with the risk of heat stroke. It manifests itself

• not only in elevated temperature,
• but also in impaired consciousness, convulsions,
• disorders of the heart and breathing.

First aid is to call the ambulance “112”.

Until the doctor arrives

• undress the child,
• move to a cool place or shade,
• supply fresh air or fan (but not cool air!),
• apply a cold compress to the forehead,
• Wipe the body with cool water or cover with a sheet soaked in cool water.

Antipyretic therapy for children should be prescribed strictly individually, taking into account clinical and anamnestic data.

It is important to know that taking antipyretic drugs does not shorten the duration of the febrile period. At the end of the drug, the temperature rises again.

Antipyretics have a lot of side effects:

• allergic reactions,
• bleeding,
• stomach damage (vomiting, regurgitation),
• Reye’s syndrome (against the background of rash, vomiting, psychomotor agitation occurs).

In addition, the decrease in body temperature should not be critical, it is not necessary to achieve normal performance. It is enough to lower the temperature by 1.0 or 1.5 degrees, which will improve the child’s well-being and avoid collapse.

The collapse develops with a critical (rapid and sharp) decrease in temperature for a short time (from 40-41 degrees to 37-36.0 degrees) by 2.5 – 3.0 degrees or more.

The result is

• acute cardiovascular insufficiency, accompanied by vasospasm and circulatory disorders.

Child feels

• cold or chilly,
• severe weakness,
• headache,
• thirsty,
• he has pale skin up to a bluish tint,
• sticky sweat,
• cold extremities,
• insomnia,
• shortness of breath up to shallow breathing,
• palpitations,
• lowering blood pressure,
• convulsions,
• loss of consciousness.

First aid before the doctor arrives:

• put the child in such a way that the head is not raised, and the legs are on the pillow (30-40 cm above the head).
• Warm up by covering the child with heating pads,
• shelter,
• rub limbs with hands,
• drink warm sweetened herbal tea, water,
• change underwear and bed linen.

It is also important to know that antipyretics should not be used in courses, as this makes it difficult to diagnose a child’s disease. An increase in temperature is often the only manifestation of a violation of the child’s health. Therefore, a doctor’s examination and additional examinations are necessary.

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reasons, recommendations of doctors of CMD Central Medical Clinic Perovo, 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.