Fever / suspected infection / sepsis
A streamlined, differential-led presentation for rapid clinical review.
Twenty-second review
- Fever reflects a regulated rise in temperature during infection or inflammation; sepsis occurs when a dysregulated response produces organ dysfunction and impaired perfusion.
- Altered mentation, hypotension, rising RR, hypoxia, mottling, oliguria, or immune compromise raises concern for severe infection.
- Keep drug fever or inflammatory disease in the differential; overlapping or concurrent illness remains possible.
- For fever / suspected infection / sepsis, trends and combinations of findings are more informative than one isolated vital sign.
Compare the clinical patterns
The repeated material is grouped inside each possibility. Open only the condition you need.
SepsisTime-sensitive high-risk possibility
HPI
Clarify suspected source; duration/max temperature; current temperature.
Signs & symptoms
Organ dysfunction, shock, meningism, severe headache, or rapidly worsening physiology.
Focused exam
Assess skin, hydration, respiratory findings, abdomen, urinary symptoms, wounds, lines, and mental status as relevant; Repeat temperature and perfusion observations; obtain collateral baseline information.
Brief pathophysiology
Sepsis may cause fever / suspected infection / sepsis through a time-sensitive process capable of rapid physiological deterioration.
What the trend may show
No single vital sign diagnoses sepsis. New tachypnea, abnormal temperature, tachycardia, or falling pressure—especially with altered mentation or poor perfusion—supports organ dysfunction and urgency.
Respiratory rate (breaths/min)
May rise earlyTachypnea is included in NEWS2 and can precede overt hypotension.
Temperature (°C)
High or lowAbsence of fever does not exclude sepsis; hypothermia is concerning.
Heart rate (bpm)
Often risesTachycardia is common but may be blunted by age or medication.
Blood pressure (mmHg)
May fallRelative hypotension and trend matter; profound hypotension can be late.
Front-load in the triage report
- Sepsis: Organ dysfunction, shock, meningism, severe headache, or rapidly worsening physiology.
- Suspected source.
- Duration/max temperature.
CNS infectionTime-sensitive high-risk possibility
HPI
Clarify duration/max temperature; current temperature; bp/hr/rr/spo2/gcs trend.
Signs & symptoms
Organ dysfunction, shock, meningism, severe headache, or rapidly worsening physiology.
Focused exam
Repeat temperature and perfusion observations; obtain collateral baseline information; Search for respiratory, urinary, abdominal, skin, line, neurologic, and medication-related sources while assessing perfusion and hydration.
Brief pathophysiology
CNS infection may cause fever / suspected infection / sepsis through a time-sensitive process capable of rapid physiological deterioration.
What the trend may show
CNS infection may produce fever and systemic illness, but classic findings and abnormal vitals can be absent. Altered mental status, rash, shock, or seizures increase urgency.
Temperature (°C)
Often elevatedFever supports infection; normal temperature does not exclude it.
Heart rate (bpm)
May riseTachycardia may reflect fever, pain, or sepsis.
Blood pressure (mmHg)
May fall with sepsisHypotension suggests systemic involvement or shock.
Blood glucose (mmol/L)
Check earlyGlucose disturbance is an important reversible mimic of altered mentation or seizure.
Front-load in the triage report
- CNS infection: Organ dysfunction, shock, meningism, severe headache, or rapidly worsening physiology.
- Duration/max temperature.
- Current temperature.
Localized infectionCommon presentation pattern
HPI
Clarify suspected source; duration/max temperature; current temperature.
Signs & symptoms
Respiratory, urinary, skin, or gastrointestinal symptoms may identify the source.
Focused exam
Assess skin, hydration, respiratory findings, abdomen, urinary symptoms, wounds, lines, and mental status as relevant; Repeat temperature and perfusion observations; obtain collateral baseline information.
Brief pathophysiology
Localized infection may explain the presenting symptoms through a common clinical mechanism, while serial assessment checks for complications or an alternate cause.
What the trend may show
No single vital sign diagnoses sepsis. New tachypnea, abnormal temperature, tachycardia, or falling pressure—especially with altered mentation or poor perfusion—supports organ dysfunction and urgency.
Respiratory rate (breaths/min)
May rise earlyTachypnea is included in NEWS2 and can precede overt hypotension.
Temperature (°C)
High or lowAbsence of fever does not exclude sepsis; hypothermia is concerning.
Heart rate (bpm)
Often risesTachycardia is common but may be blunted by age or medication.
Blood pressure (mmHg)
May fallRelative hypotension and trend matter; profound hypotension can be late.
Front-load in the triage report
- Respiratory, urinary, skin, or gastrointestinal symptoms may identify the source.
- Suspected source.
- Duration/max temperature.
Drug feverImportant alternative presentation
HPI
Clarify suspected source; duration/max temperature; current temperature.
Signs & symptoms
Medication timing or noninfectious inflammation may mimic infection.
Focused exam
Assess skin, hydration, respiratory findings, abdomen, urinary symptoms, wounds, lines, and mental status as relevant; Repeat temperature and perfusion observations; obtain collateral baseline information.
Brief pathophysiology
Drug fever can resemble fever / suspected infection / sepsis through overlapping symptoms or referred physiology despite a different primary mechanism.
What the trend may show
No single vital sign diagnoses sepsis. New tachypnea, abnormal temperature, tachycardia, or falling pressure—especially with altered mentation or poor perfusion—supports organ dysfunction and urgency.
Respiratory rate (breaths/min)
May rise earlyTachypnea is included in NEWS2 and can precede overt hypotension.
Temperature (°C)
High or lowAbsence of fever does not exclude sepsis; hypothermia is concerning.
Heart rate (bpm)
Often risesTachycardia is common but may be blunted by age or medication.
Blood pressure (mmHg)
May fallRelative hypotension and trend matter; profound hypotension can be late.
Front-load in the triage report
- Medication timing or noninfectious inflammation may mimic infection.
- Suspected source.
- Duration/max temperature.
Inflammatory diseaseImportant alternative presentation
HPI
Clarify duration/max temperature; current temperature; bp/hr/rr/spo2/gcs trend.
Signs & symptoms
Medication timing or noninfectious inflammation may mimic infection.
Focused exam
Repeat temperature and perfusion observations; obtain collateral baseline information; Search for respiratory, urinary, abdominal, skin, line, neurologic, and medication-related sources while assessing perfusion and hydration.
Brief pathophysiology
Inflammatory disease can resemble fever / suspected infection / sepsis through overlapping symptoms or referred physiology despite a different primary mechanism.
What the trend may show
No single vital sign diagnoses sepsis. New tachypnea, abnormal temperature, tachycardia, or falling pressure—especially with altered mentation or poor perfusion—supports organ dysfunction and urgency.
Respiratory rate (breaths/min)
May rise earlyTachypnea is included in NEWS2 and can precede overt hypotension.
Temperature (°C)
High or lowAbsence of fever does not exclude sepsis; hypothermia is concerning.
Heart rate (bpm)
Often risesTachycardia is common but may be blunted by age or medication.
Blood pressure (mmHg)
May fallRelative hypotension and trend matter; profound hypotension can be late.
Front-load in the triage report
- Medication timing or noninfectious inflammation may mimic infection.
- Duration/max temperature.
- Current temperature.
Findings that should escalate concern
- Altered mentation, hypotension, rising RR, hypoxia, mottling, oliguria, or immune compromise raises concern for severe infection.
- Sepsis or CNS infection: Organ dysfunction, shock, meningism, severe headache, or rapidly worsening physiology.
Medication recognition
Continue the clinical pathway
Clinical and academic sources
Curated clinical guidance and peer-reviewed evidence supporting this presentation. Current BCEHS guidance, medical direction, and local policy remain authoritative for practice.
BCEHS Handbook — specific CPGs
- K01: Infectious Diseases (General)BC Emergency Health Services Handbook
Official BCEHS clinical practice guidance for infectious diseases (general).
- K02: SepsisBC Emergency Health Services Handbook
Official BCEHS clinical practice guidance for sepsis.
Supporting clinical and academic evidence
- CEDIS Presenting Complaint List updateCanadian Association of Emergency Physicians
Presenting-complaint terminology and categorization context. It does not establish a prehospital “top 100” ranking.
- Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock 2026Society of Critical Care Medicine and European Society of Intensive Care Medicine
Contemporary sepsis physiology, perfusion, and hemodynamic context. Hospital treatment recommendations do not replace BCEHS guidance.
- Suspected sepsis in people aged 16 or over: recognition, assessment and early managementNational Institute for Health and Care Excellence
Recognition, early assessment, monitoring, risk, and limitations of isolated observations in suspected adult sepsis.
- Identification of adults with sepsis in the prehospital environment: a systematic reviewBMJ Open · 2016
Prehospital recognition of infection-related organ dysfunction and limitations of individual screening findings.