When should I go to the hospital for a fever?

When to Go to the Hospital for Fever

You should go to the hospital immediately for fever if you are an infant under 3 months of age, have a temperature above 39°C (102.2°F) with concerning symptoms, or have fever lasting more than 3 days despite treatment with antipyretics. 1, 2

Age-Based Recommendations

Infants Under 3 Months

• All neonates (<28 days) with ANY fever (≥38°C/100.4°F) require immediate emergency evaluation 1
• Infants 29-90 days with fever require risk stratification in a medical setting 1
• Rectal temperature is the gold standard for accurate measurement in this age group 1

Children 3 Months to 2 Years

Go to the hospital if:

• Temperature ≥39°C (102.2°F) with ill appearance 3, 1
• Fever persisting >3 days 2
• Signs of dehydration (decreased urination, dry mouth, no tears when crying) 1
• Presence of petechial rash (small purple/red spots that don't blanch) 1
• Inconsolable crying or irritability 1
• Difficulty breathing or bluish discoloration (cyanosis) 1

Adults

Seek immediate medical attention if:

• Temperature ≥39.4°C (103°F) with any of these risk factors 4:
  • Age ≥50 years
  • Diabetes mellitus
  • White blood cell count ≥15,000/mm³
  • Neutrophil band count ≥1,500/mm³
  • Erythrocyte sedimentation rate ≥30 mm/h
• Fever accompanied by severe headache, stiff neck, or mental confusion 3
• Immunocompromised status (HIV, chemotherapy, transplant recipients) 3
• Recent travel to malaria-endemic regions with fever 3

Warning Signs Requiring Immediate Medical Attention (All Ages)

• Altered mental status or confusion 3
• Difficulty breathing 1
• Severe headache with stiff neck 3
• Persistent vomiting or inability to keep fluids down 1
• Severe abdominal pain 1
• Seizures 1
• Petechial or purpuric rash (small purple spots that don't blanch when pressed) 1
• Extreme lethargy or difficulty waking 1

Special Considerations

Duration-Based Concerns

• Fever lasting >3 days requires medical evaluation 2
• Fever that improves but then returns may indicate secondary infection 1
• Pain that worsens or lasts >10 days with fever requires medical attention 2

Response to Treatment

• Lack of response to appropriate doses of antipyretics should raise concern 1
• Remember that response to antipyretics does NOT rule out serious bacterial infection 1

High-Risk Conditions

• Immunocompromised patients should seek medical attention for ANY fever 3, 1
• Patients with indwelling catheters or devices should have lower threshold for seeking care 1
• Patients with sickle cell disease require prompt evaluation for fever 1
• Recent travelers to malaria-endemic regions should seek immediate care for fever 3

Important Caveats

• Fever definition varies by age and measurement method, but is generally ≥38°C (100.4°F) 3, 5
• Not all serious infections present with fever; absence of fever doesn't rule out infection 3, 1
• Digital thermometers (axillary for infants, oral for older children/adults) provide more reliable measurements than temporal artery or chemical dot thermometers 3, 6
• The presence of new symptoms, redness, or swelling with fever could indicate a serious condition requiring medical attention 2

Remember that fever itself is not an illness but a symptom, and the decision to seek medical care should be based on the overall clinical picture, not just the temperature reading.