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Fever 10: Fever | Boston Children’s Hospital

Fever (0-12 Months)

Is this your child’s symptom?

  • An abnormal high body temperature
  • Fever is the only symptom. Your child has a true fever if:
  • Rectal (bottom), Ear or Forehead temperature: 100.4° F (38.0° C) or higher
  • Under the arm (armpit) temperature: 99° F (37.2° C) or higher
  • Caution: Ear temperatures are not accurate before 6 months of age
  • Caution: Forehead temperatures must be digital. Forehead strips are not accurate.

Causes of Fever

  • Overview. Almost all fevers are caused by a new infection. Viruses cause 10 times more infections than bacteria. The number of germs that cause an infection are in the hundreds. Only a few common ones will be listed.
  • Viral Infections. Colds, flu and other viral infections are the most common cause. Fever may be the only symptom for the first 24 hours. The start of viral symptoms (runny nose, cough, loose stools) is often delayed. Roseola is the most extreme example. Fever may be the only symptom for 3 to 5 days. Then a rash appears.
  • Bacterial Infections. A bladder infection is the most common cause of silent fever in girls.
  • Vaccine Fever. Fever with most vaccines begins within 12 hours. It lasts 2 to 3 days. This is normal and harmless. It means the vaccine is working.
  • Newborn Fever (Serious). Fever that occurs during the first 3 months of life can be serious. All of these babies need to be seen as soon as possible. The fever may be due to sepsis (a bloodstream infection). Bacterial infections in this age group can get worse quickly. They need rapid treatment.
  • Meningitis (Very Serious). A bacterial infection of the membrane that covers the spinal cord and brain. The main symptoms are a stiff neck, headache and confusion. Younger children are lethargic or so irritable that they can’t be consoled. If not treated early, can suffer brain damage.
  • Overheated. The fever is usually low grade. Can occur during heat waves or from being overdressed. The temp becomes normal in a few hours after moving to a cooler place. Fever goes away quickly with rest and drinking extra fluids.
  • Not Due to Teething. Research shows that “getting teeth” does not cause fevers.

Fever and Crying

  • Fever on its own shouldn’t cause much crying.
  • Frequent crying in a child with fever is caused by pain until proven otherwise.
  • Hidden causes can be ear infections, kidney infections, sore throats and meningitis.

Normal Temperature Range

  • Rectal. A reading of 98.6° F (37° C) is just the average rectal temp. A normal low can be 96.8° F (36° C) in the morning. It can change to a high of 100.3° F (37.9° C) late in the day. This is a normal range.

When to Call for Fever (0-12 Months)

Call 911 Now

  • Not moving
  • Can’t wake up
  • Severe trouble breathing (struggling for each breath; can barely speak or cry)
  • Purple or blood-colored spots or dots on skin
  • You think your child has a life-threatening emergency

Call Doctor or Seek Care Now

  • Trouble breathing, but not severe
  • Great trouble swallowing fluids or spit
  • Fever in baby less than 12 weeks old. Caution: Do NOT give your baby any fever medicine before being seen.
  • Fever over 104° F (40° C)
  • Shaking chills (shivering) lasting more than 30 minutes
  • Nonstop crying or cries when touched or moved
  • Won’t move an arm or leg normally
  • Dehydration suspected. No urine in over 8 hours, dark urine, very dry mouth and no tears.
  • Weak immune system. Examples are sickle cell disease, HIV, cancer, organ transplant, taking oral steroids.
  • Your child looks or acts very sick
  • You think your child needs to be seen, and the problem is urgent

Contact Doctor Within 24 Hours

  • Age 3-6 months old with fever
  • Age 6-12 months old with fever that lasts more than 24 hours. There are no other symptoms (such as cough or diarrhea).
  • Fever lasts more than 3 days
  • Fever returns after gone for more than 24 hours
  • You think your child needs to be seen, but the problem is not urgent

Contact Doctor During Office Hours

  • You have other questions or concerns

Self Care at Home

  • Fever with no other symptoms and your child acts mildly ill

Seattle Children’s Urgent Care Locations

If your child’s illness or injury is life-threatening, call 911.






  • Bellevue







  • Everett







  • Federal Way







  • Seattle







  • Virtual Urgent Care


Care Advice for Fever

  1. What You Should Know About Fever:
    • Having a fever means your child has a new infection.
    • It’s most likely caused by a virus.
    • You may not know the cause of the fever until other symptoms develop. This may take 24 hours.
    • For infants more than 3 months old, most fevers are good for sick children. They help the body fight infection.
    • Use the ranges below to help put your child’s level of fever into perspective:
    • 100° – 102° F (37.8° – 39° C) Low grade fever: helpful, good range. Don’t treat.
    • 102° – 104° F (39 – 40° C) Average fever: helpful. Treat if causes discomfort.
    • Over 104° F (40° C) High fever: causes discomfort, but harmless. Always treat.
    • Over 106° F (41.1° C) Very high fever: important to bring it down. Rare to go this high.
    • Over 108° F (42.3° C) Dangerous fever: fever itself can be harmful.
  2. Treatment for All FeversExtra Fluids:
    • Fluids alone can lower the fever. Reason: being well hydrated helps the body give off heat through the skin.
    • For shivering (or the chills), give your child a blanket. Make them comfortable.
    • Offer your child extra water or other fluids by mouth. Cold fluids are better. Until 6 months old, only give extra formula or breastmilk.
    • For all children, dress in 1 layer of light weight clothing, unless shivering. Reason: also helps heat loss from the skin.
    • For shivering (or the chills), give your child a blanket. Make them comfortable.
    • Caution: if a baby under 1 year has a fever, never overdress or bundle up. Reason: Babies can get over-heated more easily than older children.
  3. Fever Medicine:
    • Caution: Do not give a baby under 3 months any fever medicine. Most of these babies will need to be seen.
    • For fevers 100°-102° F (37.8° – 39°C), fever meds are not needed. Reason: fevers in this range help the body fight the infection. Fevers turn on the body’s imune system. Fevers don’t cause any discomfort.
    • Fever meds are mainly needed for fevers higher than 102° F (39° C).

  4. Give an acetaminophen product (such as Tylenol).
  5. Another choice is an ibuprofen product (such as Advil) if over 6 months old.
  6. Goal of treatment: keep the fever at a helpful level. Most often, the fever meds lower the fever by 2° to 3° F (1 – 1.5° C). They do not bring it down to normal. It takes 1 or 2 hours to see the effect.
  7. Do not use aspirin. Reason: Risk of Reye syndrome, a rare but serious brain disease.
  8. Do not use both acetaminophen and ibuprofen together. Reason: Not needed and a risk of giving too much.
  9. Pain: fever does not cause pain. If your child also has pain, it’s from the infection. It may be a sore throat or muscle pain. Treat the pain, if it’s more than mild.
  10. Return to Child Care:
    • Your child can return to child care after the fever is gone. Your child should feel well enough to join in normal activities.
  11. What to Expect:
    • Most fevers with viral illnesses range between 101° and 104° F (38.4° and 40° C).
    • They may last for 2 or 3 days.
    • They are not harmful.
  12. Call Your Doctor If:
    • Your child looks or acts very sick
    • Any serious symptoms occur such as trouble breathing
    • Fever goes above 104° F (40° C)
    • Any fever occurs if less than 12 weeks old
    • Fever without other symptoms lasts more than 24 hours
    • Fever lasts more than 3 days (72 hours)
    • You think your child needs to be seen
    • Your child becomes worse

And remember, contact your doctor if your child develops any of the ‘Call Your Doctor’ symptoms.

Disclaimer: this health information is for educational purposes only. You, the reader, assume full responsibility for how you choose to use it.

Last Reviewed: 07/16/2023

Last Revised: 12/30/2022

Copyright 2000-2023 Schmitt Pediatric Guidelines LLC.

Fever | Boston Children’s Hospital

Your child has a fever if her temperature is 100.4 degrees Fahrenheit or higher.

The body has several ways to maintain normal body temperature. 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
  • naturally wanting to seek a cooler or warmer environment

What causes a fever?

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

  • Chemicals called cytokines or mediators are produced 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 produce 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 medications
  • heat stroke
  • blood transfusion
  • disorders of the brain

What are the benefits of a fever?

A fever actually helps the body destroy its microbial invader. It also stimulates an inflammatory response, which sends all kinds of substances to the area of infection to protect the area, prevent the spread of the invader, and start the healing process.

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

Children with fevers may become more uncomfortable as the temperature rises. The following are the most common symptoms of a fever. However, each child may experience symptoms differently. In addition to a body temperature greater than 100.4 degrees Fahrenheit, symptoms may include:

  • Your child may not be as active or talkative as usual.
  • She may seem fussier, less hungry, or thirstier.
  • Your child may feel warm or hot. Remember that even if your child feels like she is “burning up,” the actual rectal or oral temperature may not be that high.

The symptoms of a fever may resemble other medical conditions. According to the American Academy of Pediatrics, if your child is younger that 2 months of age and has a rectal temperature of 100.4 degrees Fahrenheit or higher, you should call your pediatrician. If you are unsure, always consult your child’s physician for a diagnosis.

When should a fever be treated?

If your child is very uncomfortable, treatment may be necessary. Treating your child’s fever will not help her body get rid of the infection any quicker, but it will relieve discomfort associated with it.

Rarely, children between the ages of 6 months and 5 years can develop seizures from high 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.

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

Give her an anti-fever medication, 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 her temperature to rise.
  • Encourage your child to drink plenty of fluids.
  • Give your child a lukewarm bath.
  • Place cold washcloths over areas of the body where the blood vessels are close to the surface of the skin such as the forehead, wrists, and groin.

When should I call my child’s physician?

If your child’s temperature reaches 105 degrees Fahrenheit, this is considered a medical emergency and your child needs immediate medical attention, according to the American Academy of Pediatrics.

Call your child’s physician immediately if your child is younger than 3 months old and any of the following conditions are present:

  • Your child’s rectal temperature is greater than 100.4 degrees Fahrenheit.
  • Your child is crying inconsolably.
  • Your child is difficult to awaken.
  • Your child’s neck is stiff
  • Purple spots are present on the skin.
  • Breathing is difficult AND does not improve after you clear the nose.
  • Your child is unable to swallow anything and is drooling saliva.
  • Your child looks or acts very sick; if possible, check your child’s appearance one hour after your child has taken an appropriate dose of acetaminophen.

Call your child’s physician within 24 hours if your child, 3 months or older, has any of the following conditions present:

  • The fever is 102 degrees Fahrenheit or higher (especially if your child is younger than 2 years old)
  • Burning or pain occurs with urination
  • Your child has had a fever for more than 24 hours without an obvious cause or location of infection.

Call your child’s physician during office hours if any of the following conditions are present:

  • Your child has had a fever for more than 72 hours.
  • The fever went away for more than 24 hours and then returned.
  • Your child has a history of febrile seizures.
  • You have other concerns or questions.

Periodic disease (familial Mediterranean fever, search for mutations in the MEFV gene)

Mutations in exons 2, 3, 5 and 10 of the MEFV gene are the cause of the development of periodic disease (familial Mediterranean fever), a hereditary autosomal recessive disease associated with multiple repeated episodes fever and a systemic inflammatory reaction without an infectious cause.

Synonyms Russian

Familial Mediterranean fever, MEFV gene, genetic testing.

Synonyms English

Familial Mediterranean fever (FMF), gene MEFV.

Gene name

MEFV gene.

Localization of the gene on the chromosome

Locus 16p13.3.

Research method

MEFV gene sequencing.

What biomaterial can be used for research?

Venous blood.

How to properly prepare for an examination?

  • Do not smoke for 30 minutes before the test.

General information about the study

Familial Mediterranean fever (FMF) is a hereditary autosomal recessive disease caused by mutations in the MEFV gene, which encodes the pyrin protein synthesized in granulocyte cells. Most pathogenic mutations in the MEFV gene are found in exons 2, 3, 5, and 10.

Mutations in this gene result in uninhibited pyrine activity and, as a result, uncontrolled production of interleukin-1 (IL-1). IL-1 causes episodes of fever with concomitant inflammation in the peritoneum, pleura, and joints. There is also persistent subclinical inflammation.

FMF attacks are characterized by the release by neutrophils of the extracellular neutrophil trap (NET), which is a three-dimensional network formed by chromatin filaments with granular and cytoplasmic proteins located on it, including active IL-1β. NET limits its generation by a negative feedback mechanism, which explains the frequency of fevers. Presumably, episodes of fever in people with familial fever lead to excess production of amyloid A protein in the acute phase with subsequent deposition in the kidneys. However, only patients with specific MEFV haplotypes develop amyloidosis.

FMF occurs in people of different ethnic groups, but most often affects the nations historically living in the Mediterranean basin (Armenians, Jews, Arabs, Turks, Greeks and Italians), which gives the characteristic name to the disease. Currently, this disease is registered in many regions of the world.

Clinically, there are two phenotypes of FMF:

  • Type 1 is characterized by recurrent brief episodes of fever and serositis, including peritonitis, synovitis, pleurisy, and less frequently pericarditis and meningitis. Symptoms and their severity vary from patient to patient, sometimes even within the same family. Amyloidosis, which can lead to kidney failure, is the most serious complication if left untreated.
  • type 2 is characterized by the presence of only amyloidosis.

Clinical manifestations:

– Most common: recurrent fever, peritonitis, pleurisy, pericarditis, amyloidosis.

– Less common: prolonged febrile myalgia, erysipelatous skin erythema, vasculitis (Schoenlein-Henoch purpura and periarteritis nodosa), recurrent urticaria, aseptic meningitis, reduced fertility.

What is research used for?

In accordance with international clinical guidelines, a genetic examination for a periodic disease is carried out if the patient has clinical symptoms characteristic of this disease, as well as relatives and children of the patient.

When is the test ordered?

  • Differential diagnosis of fever of unknown origin;
  • for suspected periodic illness;
  • in the differential diagnosis of serositis such as peritonitis, synovitis, pleurisy, pericarditis and meningitis;
  • in the differential diagnosis of amyloidosis;
  • with early detection of the disease in relatives;
  • when planning a family.

What do the results mean?

Genetic testing is the main method of confirming the diagnosis and is based on the detection of mutations using Sanger sequencing in the MEFV gene. Since FMF is an autosomal recessive disease, detection of a homozygous mutation or two heterozygous mutations is required to confirm the diagnosis. The presence of a single heterozygous mutation increases the likelihood of a diagnosis of FMF and justifies initiation of colchicine therapy.

Reference values ​​

No mutations were found in exons 2, 3, 5 and 10 of the MEFV gene.

Positive result

A pathological mutation in the MEFV gene, characteristic of familial Mediterranean fever, was detected.

What can influence the result?

Although the genetic test is an accurate method of laboratory diagnosis, the time of clinical manifestations of the disease (penetrance of the disease) depends on the external environment, individual genetic factors. To assess the nature of inheritance in children and relatives, the risk of progression of the disease and the appointment of treatment, it is recommended to consult a specialist.

Important Notes

  • A clinical geneticist should be consulted to obtain a conclusion on the test result.

Who orders the examination?

Rheumatologist, general practitioner, geneticist.

Also recommended

[02-029] Clinical blood test: complete analysis, leukocyte count, ESR (with blood smear microscopy if pathological changes are detected)

[13-059] Connective tissue disease screening

[13-007] Double-stranded DNA antibodies (anti dsDNA), screening

[13-048] Antiperinuclear factor

[13-020] Rheumatoid factor 90 003

Literature

  • Saul RA, Tarleton JC. FMR1-Related Disorders. 1998 Jun 16 [Updated 2012 Apr 26]. In: Adam MP, Ardinger HH, Pagon RA, et al. , editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2018.
  • D’Hulst C, Kooy RF Fragile X syndrome: from molecular genetics to therapy Journal of Medical Genetics 2009;46:577-584.
  • Pugin A, Faundes V, Santa María L, Curotto B, Aliaga S, Salas I, et al. Clinical, molecular, and pharmacological aspects of FMR1-related disorders. Neurol (English Ed 2017;32:241–52.
  • Wheeler AC, Bailey Jr DB, Berry-Kravis E, Greenberg J, Losh M, Mailick M, et al. Associated features in females with an FMR1 premutation. J Neurodev Disord 2014;6:30.

Yellow fever – Udmurt AIDS Center

Yellow fever is an acute viral hemorrhagic disease transmitted by infected mosquitoes. “Yellow” it is called because of the jaundice that develops in some patients. Up to 50% of people who develop severe illness die from yellow fever. An estimated 200,000 cases of yellow fever occur worldwide every year, 30,000 of which are fatal, 90% of them in Africa. This virus is endemic in tropical regions of Africa and Latin America with a total population of more than 900 million people. Over the past two decades, the number of cases of yellow fever has increased as a result of declining population immunity to infection, deforestation, urbanization, population migration and climate change.

There is no cure for yellow fever. Only symptomatic treatment is possible, aimed at alleviating symptoms for a more comfortable condition of patients. Vaccination is the most important measure to prevent yellow fever. The vaccine is safe, affordable and highly effective. It provides protection for 30-35 years or more. For 9In 5% of vaccinated people, the vaccine provides effective immunity one week after immunization. Yellow fever vaccination is highly recommended for those traveling outside urban areas in endemic countries (Africa and South America) that do not officially report cases and do not usually require a certificate to enter the country.

Vaccination against yellow fever is nearly 100% effective, while mortality from the disease reaches 60% in non-immune adults. The tolerability of modern vaccines is excellent. The only contraindication, in addition to a true allergy to the protein of chicken eggs, is the insufficiency of cellular immunity (congenital or acquired, the latter can only be temporary). A vaccination certificate can only be valid if it meets the requirements for its issuance and if the vaccine used is approved by WHO and the vaccination was given at a certified yellow fever vaccination center.

The validity of the vaccination certificate is 10 years, starting from the 10th day after the day of vaccination. If a person is revaccinated before the expiration of this period, the validity is extended for a further 10 years, starting from the date of immunization. If the revaccination is recorded on a new certificate form, it is recommended to keep the previous vaccination certificate for 10 days from the date of the revaccination, until the expiration date of the new certificate begins.

List of countries requiring an international yellow fever vaccination certificate97 No. 2510/4106-97-32 “On changing the requirements for vaccination against yellow fever when Russian citizens travel to foreign countries”)

  • Benin
  • Burkina Faso
  • Gabon
  • Ghana
  • Zaire
  • Cameroon
  • Congo
  • Ivory Coast
  • Liberia
  • Mauritania
  • Mali
  • Niger
  • Rwanda
  • Sao Tome and Principe
  • Togo
  • French Guiana
  • Central African Republic
  • South America Africa Venezuela Angola Bolivia Burundi Brazil Gambia Guyana Guinea Colombia Guinea-Bissau Panama Zambia Suriname Kenya Ecuador Nigeria Senegal Somalia Sudan Sierra Leone Tanzania Uganda Chad Equatorial Guinea Ethiopia

    Tourists are advised to get vaccinated against yellow fever

    Russian epidemiologists urge citizens leaving for some countries of South America and Africa to get vaccinated against yellow fever. According to the World Health Organization, the number of people infected with this disease has increased significantly in recent years.

    The Federal Service for Supervision of Consumer Rights Protection and Human Welfare told MK that deadly mosquito bites have become more frequent in Guinea, Brazil and the Gambia, and in Mali yellow fever has been reported for the first time in 10 years. At the same time, only 16 countries require tourists to have an international certificate of vaccination. Another 27 countries where there are outbreaks of the epidemic are limited to recommendations to get vaccinated before entering the country. These are Angola, Burundi, Gambia, Guinea, Guinea-Bissau, Kenya, Mauritania, Nigeria, Senegal, Sierra Leone, Somalia, Sudan, Uganda, Tanzania, Chad, Equatorial Guinea, Bolivia, Brazil, Venezuela, Guyana, Guiana, Colombia, Panama, Peru, Suriname, Trinidad and Ecuador. In a word, tourists going there should take care of their own safety. And the only way of salvation that medicine can offer people today is a vaccine that is valid for 10 years.