Pediatric Fever Nursing CE Course for APRNs

tely measured to characterize the level of fever. Body temperature for outpatient clinical purposes in infants and very young children (under 3 years of age) is generally measured rectally. Oral thermometers can be used in children who are able to cooperate, but mouth breathing and tachypnea during illness may diminish the accuracy (Wallace, 2025). According to the American Academy of Pediatrics (American Academy of Pediatrics [AAP], 2024), rectal temperatures are more accurate, but caution should be exercised to avoid bowel perforation. Caregivers should also no longer be using a mercury thermometer. Refer to Table 1 for more information regarding various options for digital thermometers available.

Table 1

Digital Thermometers 

Digital multi-use thermometer How it works: reads the body temperature when the sensor tip touches that part of the body Where it works: rectal (birth to age 3); oral (age 4 and up); axillary (screening only, any age) Notes: Label “oral” or “rectal” and do not use in both places; axillary is the least reliable but is acceptable for screening in schools/childcare centers

Temporal artery How it works: reads the infrared heat waves released by the temporal artery Where it works: on the front or side of the forehead Notes: more accurate in infants 3 months and older; acceptable for screening in infants 0–2 months

Tympanic How it works: reads the infrared heat waves released by the eardrum Where it works: essential to place it correctly in the ear canal for accuracy Notes: not reliable in infants under 6 months; ear canal must be clear of earwax for accuracy

(AAP, 2024)

A comprehensive physical exam should also be performed to determine possible sources of infection and accompanying symptoms. Vital signs should be assessed, noting any tachycardia or tachypnea when examining the cardiopulmonary systems. The nasal passages and oropharynx should be observed for lesions that could indicate herpes gingivostomatitis or Coxsackie virus. Abdominal examination should include assessment for suprapubic or costovertebral angle (CVA) tenderness. A skin survey should identify and characterize rashes, lesions, cellulitis, petechiae, or other unexpected findings while examining for any lymphadenopathy. A complete head-to-toe musculoskeletal exam focusing on infection is essential, with notation of pain with palpation or passive range of motion (Allen, 2026; Palazzi, 2025).

 

Infants 90 Days or Less

Patients under 3 months old should be evaluated by a provider for any temperature over 38° C (100.4° F). The infant can be evaluated in an outpatient office setting unless they appear lethargic or hypotonic; then an emergency room evaluation would be more appropriate (NICE, 2021; Smitherman et al., 2025). Current guidelines suggest that risk stratification should be done carefully in infants with a fever, and the infant’s appearance should be seriously considered, along with the temperature level. In infants 30–60 days old, risk stratification recommends obtaining urinalysis (UA), urine culture (UC), complete blood count (CBC), and blood cultures. A chest radiograph (CXR) would be performed if any respiratory symptoms are present. A C-reactive protein (CRP) and procalcitonin (PCT) level should be drawn to determine if the infant is at high or low-risk for invasive bacterial infection (IBI). High-risk infants would also have a cerebrospinal fluid (CSF) assessment (NICE, 2021). The Pediatric Emergency Care Applied Research Network algorithm can be utilized in low-risk infants with fever (Smitherman et al., 2025).

In a young infant, a thorough history that includes prenatal and perinatal information is vital. Additional information regarding feeding, elimination, and sleeping changes should be obtained as well as potential contact exposure to ill family members. In addition to updated vital signs, the physical examination should evaluate airway and breathing effort, perfusion and oxygenation, as well as the skin for rashes or cellulitis (Jordan et al., 2025). If the child appears well, has a reliable caregiver, and the white blood cell count (WBC), CBC, UA, CSF, and CXR are negative, they are considered low-risk and may be discharged under the observation of a caregiver with a follow-up appointment within 24 hours. Further treatment should be initiated based on the results of blood cultures (NICE, 2021).

 

Older Infants and Toddlers

In children 3–36 months old, evaluation becomes less stratified, as even severely elevated temperature in children of this age range may not indicate severe infection. Children between 3 and 36 months of age with a fever over 39° C (102.2° F) should be evaluated by a provider and managed based on their appearance. In fully immunized children, the incidence of bacteremia is less than 1%. Despite this statistic, a toxic-appearing child, or a child with unstable vital signs, should be managed as if they have sepsis (Allen, 2026). Once the child presents to the emergency department, triage personnel can utilize the Emergency Severity Index (ESI) tool to quickly determine which of the five levels of care they require. This tool is designed to assess four decision points quickly to determine the urgency of care and anticipated resources. These four points include whether a lifesaving intervention is needed, if the child is at high risk, the number of resources that will be required, and assessment of the acuity level. ESI level 1 is the most critical and requires the most resources, while ESI level 5 requires only a physical examination (Ohns, 2025).

In well-appearing children, immunization status is the determining factor for the intensity of the workup required. CBC with differential and serum PCT levels should be drawn in a febrile child who is unimmunized or partially immunized without an obvious source of infection. UA and/or culture should also be done. If urine testing indicates a probable UTI, empiric antibiotics should be initiated. Patients in this demographic group with an elevated PCT level (above 0.5 ng/mL), WBC count above 15,000/microL, and/or ANC above 10,000/microL should have blood cultures drawn. A CXR should also be performed if the WBC is 20,000/microL or greater. If infiltrates are present on CXR, blood cultures and empiric antibiotics are recommended (Allen, 2026).

Fully immunized children between 3 and 36 months typically do not require these tests due to the lower risk of occult bacteremia. However, they are still at risk for UTI. All children should have a UA/UC done if they have prolonged (>48 hours) fever, symptoms of UTI, have had recent UTI, have genital abnormalities, are uncircumcised males under the age of 12 months (or circumcised but under 6 months), or are females under the age of 24 months. If not toilet-trained, toddlers may require catheterization to obtain a sample (Allen, 2026). A child may be categorized as low-risk if they have average or expected coloring in their skin, lips, and tongue, are occasionally smiling, are reacting as expected to others socially, are awake/alert, are either not crying or crying forcefully, and appear well-hydrated with moist mucous membranes, a brisk capillary refill, and good skin turgor (NICE, 2021).

 

Older Children

A provider should also evaluate patients older than 36 months with a fever and focal symptoms or who do not appear otherwise well. Lab values and tests should be ordered in these children based on exam findings and correlated symptoms (Wallace, 2025). Systemic inflammatory response syndrome (SIRS) and sepsis should be considered when a child over 36 months has a fever over 38.5° C (101.3° F) with tachycardia, tachypnea, or leukocytosis. Of note, SIRS and sepsis may also be considered in the absence of fever if the child has any combination of tachycardia, tachypnea, or leukocytosis. The diagnostic criteria for SIRS include a core temperature over 38.5° C (101.3° F) or under 36° C (96.8° F), tachycardia that is greater than two standard deviations above average given the patient’s age, tachypnea that is greater than two standard deviations above average given the patient’s age, or a leukocyte count that is elevated (or depressed) or with >10% immature neutrophils. At least two must be present to diagnose SIRS, and at least one must be an elevated temperature or leukocytosis. When SIRS is present with a suspected or confirmed infection, sepsis can be diagnosed. Severe sepsis involves the presence of cardiovascular dysfunction, acute respiratory distress syndrome, or organ dysfunction seen in at least two (or more) other organ systems (Pomerantz & Carlton, 2025). A non-blanching rash with larger lesions (>2 mm) and/or neck pain or stiffness should raise suspicion for meningitis. Other signs may include prolonged capillary refill, decreased level of consciousness, a high-pitched cry, an overall ill appearance, or seizure activity (NICE, 2021).

             

Fever Management

Treatment of fever has not been found to decrease adverse events or worsen the illness in otherwise healthy children. Treating fever in an otherwise healthy child should be based on the caregiver and child’s wishes to reduce discomfort. A downside of treating fever with antipyretic agents is that it affects the provider’s ability to assess the temperature duration and may delay the identification of the underlying etiology. The ultimate goal of fever treatment in these patients is simply to increase the child’s comfort level and potentially prevent fluid loss. Therefore, the initial therapy for fever should consist of rest and additional oral fluid intake. The treatment of fever is recommended if over 40° C (104° F) or in children who have underlying conditions that increase metabolism and limit their ability to tolerate the increased metabolic demands, have had significant head trauma, are post-cardiac arrest, are in shock, or have fluid or electrolyte alterations. If the child is uncomfortable or exhibits decreased activity level or fluid intake, the fever may be treated with an antipyretic agent, such as acetaminophen (Tylenol, Paracetamol) or ibuprofen (Advil, Motrin) in recommended doses. Care should be taken when combining antipyretic medication with other cough or cold medications that may also contain the same antipyretic ingredient and lead to higher than recommended doses (Wallace, 2025). Ibuprofen (Advil, Motrin) has been found to be slightly more effective as an antipyretic in children and may reduce pain better in children under the age of two when utilized in the first 24-hour period. Both acetaminophen (Tylenol, Paracetamol) and ibuprofen (Advil, Motrin) have similar safety and adverse event profiles. Many providers recommend acetaminophen (Tylenol, Paracetamol) as the first-line antipyretic for children due to its longer and more researched safety history (Tan et al., 2020).

There may be an increased risk of kidney injury in the setting of ibuprofen (Advil, Motrin) in a febrile child who is dehydrated, and acetaminophen (Tylenol) is contraindicated in children with liver failure. The combination of ibuprofen (Advil, Motrin) and acetaminophen (Tylenol) has also been found to be more effective in reducing fever, but most studies have failed to demonstrate that this is clinically significant. This combination of agents is typically not recommended due to the increased risk of dosage error and the potential for kidney or liver injury. Acetaminophen can be given to infants at least 3 months old at 10-15 mg/kg/dose every 4–6 hours, with a maximum of 1 g/dose and 75 mg/kg (4 g)/day. It should not be given more than five times per 24 hours. Ibuprofen can be given safely to children at least 6 months old at 10 mg/kg/dose every 6 hours, with a maximum of 600 mg/dose and 40 mg/kg (2.4 g)/day. Both medications typically start to work within an hour and peak in 3–4 hours. If significant relief is not seen after the initial dose, it is reasonable to switch from acetaminophen to ibuprofen or vice versa (Wallace, 2025).

Aspirin should not be administered for fever to avoid the potential for Reye syndrome (Wallace, 2025). Caregivers often have already treated the child’s fever prior to bringing them for medical evaluation. Caregivers do not always seek advice on proper dosing of antipyretic products and education may need to be initiated at routine office visits to ensure proper dosing when needed. Research on caregiver preferences demonstrated the increased use of acetaminophen (Tylenol, Paracetamol) over ibuprofen (Advil, Motrin), with caregivers’ familiarity with the product as the underlying reason for the choice (Alqudah et al., 2025).

Antibiotics and Other Treatment Measures

Gram-negative organisms are present in the majority of infections in infants younger than 90 days of age. Empiric antibiotics are indicated for fever alone in infants under 60 days old who are determined to be at high risk based on the criteria discussed above. In infants 8–21 days old, recommended empiric antibiotics include ampicillin (Unasyn) 150 mg/kg/day IV divided every 8 hours and either ceftazidime (Fortaz) 150 mg/kg/day IV or IM divided every 8 hours or gentamycin (Garamycin) 4 mg/kg IV or IM once daily. If bacterial meningitis is suspected, the ampicillin (Unasyn) dose should be increased to 300 mg/kg/day divided every 6 hours, and the ceftazidime (Fortaz) can be used, but not gentamycin (Pantell et al., 2021).

In infants between 22 and 60 days old, ceftriaxone (Rocephin) 50 mg/kg/day IV or IM daily is recommended in those with a suspected UTI or no identified focus. In infants able to receive oral antibiotics (over 28 days), cephalexin (Keflex) 50-100 mg/kg/day may be given PO in four divided doses, or cefixime (Suprax) 8 mg/kg/day PO daily should be utilized. In infants between 28 and 60 days with a fever that is suspected to be related to meningitis, the empirical antibiotics recommended include vancomycin (Vancocin) 60 mg/kg/day IV divided every 8 hours and either ceftriaxone (Rocephin) 100 mg/kg/day IV once daily or divided every 12 hours or ceftazidime (Fortaz) 150 mg/kg/day IV divided every 8 hours (Pantell et al., 2021). Infants between 60 and 90 days should be hospitalized for additional evaluation as described previously and given empiric antibiotics if risk factors for IBI are present. Infants can often be managed at home with close observation if previously healthy and without any risk factors. If UTI is suspected based on UA, the oral antibiotic should cover Escherichia coli and consider local resistance patterns (Smitherman et al., 2025).

Regardless of vaccination status, all young children (3–36 months) should receive empiric antibiotics with coverage for E. coli based on local resistance patterns if their urine testing indicates probable UTI. In young children (3–36 months) who are not vaccinated (or incompletely vaccinated) with infiltrates present on CXR, empiric antibiotics such as ceftriaxone (Rocephin) 50 mg/kg IM (with coverage for Streptococcus pneumoniae based on local resistance patterns) are recommended initially until blood culture results are available. This aged child may be discharged if well-appearing with good oral intake and solid family support. Otherwise, they should be admitted for care. In young children (3–36 months) who are fully vaccinated without risk factors or abnormal UA results, it is most likely that a virus would cause a fever, and empiric antibiotics are not advised (Allen, 2026).

Empiric antibiotics are not warranted in children over 36 months of age unless shock or sepsis is suspected. If SIRS or sepsis is suspected, first fluid resuscitation and culture (blood, urine, and potentially including CSF culture per facility protocol) must be conducted. Further treatment of these children should be managed in a pediatric intensive care unit and is beyond the scope of this article (Pomerantz & Carlton, 2025). Initiation of antibiotic treatment not in the setting of sepsis or SIRS should be based on clinical findings. In these instances, empiric antibiotics are not warranted without an identified source of infection, as fever alone is not an indication for the prescription of antibiotics (NICE, 2021). For caregivers of children over 3 years old, extensive education should be provided that antibiotics are not indicated without an identified source of infection to help with understanding (Wallace, 2025).

Fever of Unknown Origin

A persistent fever over 38.3° C (101° F) that has been present for longer than 7 days with no identified source after the initial evaluation is called a FUO. While infections are common, other potential causes include inflammatory, neoplastic, and miscellaneous sources. A comprehensive list of underlying etiologies for FUOs is beyond this course’s scope; however, leading rheumatologic disorders include juvenile idiopathic arthritis and systemic lupus erythematosus, while neoplastic disorders include leukemia and lymphoma as the top two contributing malignancies. It should also be noted that FUOs often resolve spontaneously without the causal etiology ever being identified. When evaluating a child with this type of fever, it is crucial to repeat an extensive history (Palazzi, 2025; Trapani et al., 2024).

FUOs are often common diseases presenting abnormally; therefore, the history of potential recent exposures to pathogens is critical. Possible exposures should be reviewed, including travel history, insect or animal bites or scratches, previous illnesses, sick contacts, medications, and recent laboratory tests. History should include how frequently the child’s temperature is being taken as well as the fever pattern throughout the day, with notation of response to antipyretic administration. This may be best collected via a fever diary. A gap of a few days without any fever may indicate two consecutive but separate viral infections. Abnormalities in weight, heart rate, or blood pressure can also provide clues to the origin of the fever. A focused accounting of the history of events and associated symptoms, followed by a comprehensive physical examination, is vital to determine the potential source of the fever (Palazzi, 2025; Trapani et al., 2024).

Initial labs should include CBC and peripheral smear, comprehensive metabolic panel (CMP), UA/UC, blood cultures, erythrocyte sedimentation rate, CRP, and a CXR. Further testing and imaging should be determined by the obtained history, physical exam, and accompanying symptoms. An additional option for testing a child with FUO is a viral polymerase chain reaction panel, which can identify common viral pathogens such as adenovirus, influenza, and respiratory syncytial virus. Cytomegalovirus and Epstein-Barr virus may need to be ruled out. If the patient’s CBC indicates a high level of bands (immature WBCs), the provider may consider checking their lactate dehydrogenase, uric acid, and ferritin levels to rule out an oncologic process. A referral to a pediatric oncologist should be considered if the peripheral smear and laboratory values discussed above are abnormal or in the context of night sweats or weight loss. An antinuclear antibody, complement level, and a referral to a pediatric rheumatologist should be considered if rheumatologic etiology is suspected. A trial of empiric antibiotics or anti-inflammatories should be avoided in these patients unless the evidence suggests juvenile arthritis or a life-threatening infection such as typhoid or malaria, as antibiotics could mask other potential etiologies (Palazzi, 2025).

Febrile Seizures

Febrile seizures are fairly common. They can occur in pediatric patients and are associated with fever without other co-morbid intracranial abnormalities or infections. Children with a genetic predisposition can be more susceptible to febrile seizures. Viruses, bacteria, or vaccines can be causative agents of febrile seizures. Febrile seizures can be classified as simple, complex, or symptomatic. Simple febrile seizures last less than 15 minutes, are generalized, and occur once within 24 hours with no focal component. Complex febrile seizures last longer than 15 minutes, have a focal component, and occur more than once in 24 hours. A symptomatic febrile seizure occurs due to a fever in a child with a preexisting neurological abnormality. Simple febrile seizures do not require extensive evaluation other than identifying the source of the fever. Children presenting with complex seizures or with evidence of neurological deficits should be evaluated further with CMP, blood and UCs, and CSF analysis. Acute management of a febrile seizure involves maintaining a patent airway, ensuring effective breathing, loosening clothing, administering oxygen therapy as needed, and protecting the patient from injury by placing them in a semi-prone position. The fever should be treated according to duration and severity. For any seizure lasting longer than 5 minutes, IV lorazepam (Ativan) or diazepam (Valium) is generally effective, while monitoring for potential respiratory depression. If IV access is not available, buccal administration of midazolam (Versed) or rectal diazepam (Valium) can be utilized. In patients with persistent seizures, phenobarbital (Luminal), valproate (Depakote), or levetiracetam (Keppra) is indicated (Millichap, 2025; Victorio, 2025).

Future Research/Directions

 

Medicine has been using 37° C (98.6° F) as the determined benchmark for the average body temperature for over a century. As stated previously, recent research has suggested that the mean body temperature is actually lower due to physical changes in the human body and the extended life span over the past century. The general definition of normal body temperature and advised fever limits needs continued investigation (Protsiv et al., 2020). Further investigation is also needed into the accuracy of devices utilized to measure body temperature, as medical decision-making is based on the readings obtained. As mercury-based thermometers have been replaced by electronic devices, concern is present regarding the accurate measurement of temperature with these devices. Current electronic thermometers use contact or non-contact methods to collect data. Electronic devices require calibration to ensure accuracy. Use over time, as well as incidents such as dropping the device, can diminish the accuracy of the equipment. Electronic devices utilized in medical facilities should undergo scheduled evaluations of calibration accuracy to safely and reliably direct care interventions (Machin et al., 2021).

References

Allen, C. H. (2026). Fever without a source in children 3 to 36 months of age: Evaluation and management. UpToDate. Retrieved March 6, 2026, from https://www.uptodate.com/contents/fever-without-a-source-in-children-3-to-36-months-of-age-evaluation-and-management

Alqudah, M., Stubbs, M. A., Al-Masaeed, M., & Fernandez, R. (2025). An evaluation of parents’ and caregivers’ preferences managing fever in children based on experiences in using ibuprofen and paracetamol: A systematic review. Journal of Pediatric Nursing, 80, e272-e281. https://doi.org/10.1016/j.pedn.2024.12.018

American Academy of Pediatrics. (2024). How to take your child’s temperature. https://www.healthychildren.org/English/health-issues/conditions/fever/Pages/How-to-Take-a-Childs-Temperature.aspx

Becker, J. U. (2025). Fever in the child returning from global travel. Pediatric Emergency Medicine Reports, 30(10), 1-28. https://www.clinician.com/articles/fever-in-the-child-returning-from-global-travel

Bush, L. M. (2025). Fever. Merck Manual Professional Version. https://www.msdmanuals.com/professional/infectious-diseases/biology-of-infectious-disease/fever

Jordan, K. S., Steelman, S. H., & McInnis, E. C. (2025). Reducing the risk: An evidence-based approach to the febrile infant less than 60 days of age in the emergency department. Advanced Emergency Nursing Journal, 47(1), 23-30. https://doi.org/10.1097/TME.0000000000000547

Machin, G., Brettle, D., Fleming, S., Nutbrown, R., Simpson, R., Stevens, R., & Tooley, M. (2021). Is current body temperature measurement practice fit-for-purpose? Journal of Medical Engineering & Technology, 45(2), 136-144. https://doi.org/10.1080/03091902.2021.1873441

Millichap, J. J. (2025). Treatment and prognosis of febrile seizures. UpToDate. Retrieved March 10, 2026, from https://www.uptodate.com/contents/treatment-and-prognosis-of-febrile-seizures

National Institute for Health and Care Excellence. (2021). Fever in under 5s: Assessment and initial management. NICE Guideline, No. 143. https://www.ncbi.nlm.nih.gov/books/NBK552086

Ohns, M. J. (2025). Pediatric fever in the emergency department: Triage to caregiver education. Journal of Emergency Nursing, 51(1), 10-19. https://doi.org/10.1016/j.jen.2024.09.006

Palazzi, D. L. (2025). Fever of unknown origin in children: Evaluation. UpToDate. Retrieved March 6, 2026, from https://www.uptodate.com/contents/fever-of-unknown-origin-in-children-evaluation

Pantell, R. H., Roberts, K. B., Adams, W. G., Dreyer, B. P., Kuppermann, N., O’Leary, S. T., Okechukwu, K., Woods, C. R., Jr., & Subcommittee on Febrile Infants (2021). Evaluation and management of well-appearing febrile infants 8 to 60 days old. Pediatrics, 148(2), e2021052228. https://doi.org/10.1542/peds.2021-052228

Pomerantz, W. J. & Carlton, E. (2025). Sepsis in children: Definitions, clinical manifestations, and diagnosis. UpToDate. Retrieved March 6, 2026, from https://www.uptodate.com/contents/sepsis-in-children-definitions-clinical-manifestations-and-diagnosis

Protsiv, M., Ley, C., Lankester, J., Hastie, T., & Parsonnet, J. (2020). Decreasing human body temperature in the United States since the industrial revolution. eLife, 9, e49555. https://doi.org/10.7554/eLife.49555

Smitherman, H. F., Macias, C. G., & Mahajan, P. (2025). The febrile infant (29 to 90 days of age): Management. UpToDate. Retrieved March 6, 2026, from https://www.uptodate.com/contents/the-febrile-infant-29-to-90-days-of-age-management

Tan, E., Braithwaite, I., McKinlay, C. J. D., & Dalziel, S. R. (2020). Comparison of acetaminophen (Paracetamol) with ibuprofen for treatment of fever or pain in children younger than 2 years: A systematic review and meta-analysis. JAMA Network Open, 3(10), e2022398. https://doi.org/10.1001/jamanetworkopen.2020.22398

Trapani, S., Fiordelisi, A., Stinco, M., & Resti, M. (2024). Update on fever of unknown origin in children: Focus on etiologies and clinical approach. Children (Basel), 11(1):20. https://doi.org/10.3390/children11010020

Victorio, M. C. (2025). Febrile seizures. Merck Manual Professional Version. https://www.msdmanuals.com/professional/pediatrics/neurologic-disorders-in-children/febrile-seizures

Wallace, S. S. (2025). Fever in infants and children: Pathophysiology and management. UpToDate. Retrieved March 6, 2026, from https://www.uptodate.com/contents/fever-in-infants-and-children-pathophysiology-and-management

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