During cold and flu season, pediatric patients will often present with low and high grade fever in clinic. While some fevers may be no cause for concern, fevers above certain thresholds can cause acute harm for children of various age groups. Use this clinician-focused resource to determine whether fevers require emergency intervention or can be managed at home.
Age-Based Fever Risk
During crucial developmental periods, fevers can cause profound stress on a patient’s body. The child’s appearance and age matter more than the number on the thermometer. With elevated body temperatures, dangerous complications like increased metabolic rate, oxygen consumption, insensible fluid losses, and cardiovascular demand can occur. Use this data to evaluate risk and determine course of action:
- <28 days old: Any fever ≥38.0°C (100.4°F) is dangerous → Immediate evaluation
- 29–60 days old: Fever ≥38.0°C → Urgent same-day evaluation
- 3–6 months: Fever ≥39.0°C (102.2°F) → Evaluate
- >6 months: Assess context and red flags below
Related: Rx Essentials: Pediatric Prescribing & Sick Visit Challenges
Behavioral Warning Signs
The way a child behaves when being examined can provide context into how serious their fever is, and whether further intervention is necessary. Look out for these signs during sick visits:
- Lethargic, difficult to arouse, or unresponsive
- Weak cry, high-pitched cry, or moaning
- Poor eye contact, not tracking caregivers
- Inconsolable irritability or persistent screaming
- Floppy or hypotonic
- Child looks “toxic” or markedly ill
Conversely, if a child is alert, awake, can make eye contact, or has the energy to smile or play, this patient’s fever may not warrant emergency care.
Physiological Red Flags
Breathing dysfunction can be a major cause for concern. Look out for labored breathing, cyanosis, mottling, or pale/gray skin, weak pulse, and capillary refill >3 seconds. Hydration levels may also be used to determine whether a child needs high-level care. Use this guide:
No urine for:
- 8 hrs (infants)
- 12 hrs (toddlers)
- 24 hrs (older children)
☐ Dry mucous membranes
☐ Sunken eyes or fontanelle
☐ Persistent vomiting or inability to keep fluids down
Indications of sufficient hydration regulation include tear production when crying, intake of fluids, and regular wet diapers/urination.
Fever Characteristics
More concerning
☐ Fever ≥40.0°C (104°F)
☐ Fever lasting:
- 48 hrs in children <2 years
- 72 hrs in children ≥2 years
☐ Fever not improving with antipyretics
☐ Recurrent or relapsing fever pattern
Less concerning
☐ Fever responds to acetaminophen/ibuprofen
☐ Child improves when fever decreases
Communicating with Parents
Parents of children with fevers—especially those with a myriad of other symptoms—may feel anxious, overwhelmed, or frustrated. It’s your job to be truthful and remain calm when interacting with a distressed parent. Don’t be overly alarmist if a child’s fever raises red flags, and do not be dismissive if a child’s fever appears to be benign. Share these warning signs with parents, and advise them to watch out for worsening symptoms. Assure them that their child’s fever will most likely pass with time, and if it doesn’t, remind them that you are always there to help. It can be helpful to give caregivers a simple red flag checklist, including:
- Child becomes hard to wake or unresponsive
- Breathing worsens
- Rash appears or spreads
- Fever persists beyond advised timeframe
- Child stops drinking or urinating
- Parental concern escalates
Related: Common Pediatric Issues: Assessment & Treatment CH:14.3 (8.5 Rx)
