Browse categories and answer follow-up questions to refine your symptom profile.
History
Exposure details
Cold exposure context
Ambient temperature
Wind exposure
Wet clothing
Water immersion
Duration of exposure
Shelter availability
Clothing adequacy
Heating failure
OPQRST
Onset
Time last known normal
Time found
Provocation and palliation
Worse with continued exposure
Improvement with warming
Alcohol use preceding exposure
Exertion preceding collapse
Quality
Feeling cold
Shivering
Confusion
Clumsiness
Region and radiation
Local cold injury location
Distal extremity involvement
Severity
Functional impairment
Ability to ambulate
Ability to speak coherently
Timing
Progressive decline
Sudden collapse
Associated symptoms
Symptoms suggesting alternate or precipitating diagnosis
Chest pain
Dyspnea
Syncope
Head trauma
Seizure
Infection symptoms
Polyuria polydipsia
Endocrine symptoms
Prior episodes and baseline
Baseline function
Cognitive baseline
Mobility baseline
Prior hypothermia
Prior cold injuries
Prior rewarming complications
Alarm Features
Immediate resuscitation triggers
Time critical instability
Cardiac arrest
Unstable bradycardia with hypotension
Ventricular arrhythmia
Core temperature less than 32 C with altered mental status
Core temperature less than 28 C
Refractory hypotension
Respiratory failure
High risk history triggers
High risk features
Water immersion
Avalanche burial
Prolonged exposure
Intoxication with impaired thermoregulation
Hypoglycemia risk
Trauma mechanism
Dangerous vital sign patterns
Hypothermia physiology red flags
Progressive bradycardia with declining mental status
Hypotension after rewarming initiation
Hypoventilation
Oxygen saturation unreliable with poor perfusion
Shivering absent in a cold patient
Medications
Current medications
Medication contributors
Sedatives
Opioids
Antipsychotics
Beta blockers
Alpha agonists
Insulin
Oral hypoglycemics
Recent changes
Recent medication changes
Dose escalation
New sedating medication
Contraindications and interactions relevant to treatment
Rewarming and resuscitation interaction risks
Anticoagulants with frostbite thrombolysis consideration
QT prolonging drugs with hypothermia related QT prolongation
Diet
Intake and hydration
Recent intake pattern
Poor oral intake
Dehydration risk
Malnutrition risk
Substances affecting thermoregulation
Exposure pattern
Alcohol
Stimulants
Cannabis edibles
Energy drinks
Review of Systems
General and constitutional
General symptoms
Fever
Weight loss
Fatigue
Night sweats
Cardiopulmonary
Cardiorespiratory symptoms
Chest pain
Dyspnea
Palpitations
Cough
Hemoptysis
Neurologic
Neurologic symptoms
Confusion
Syncope
Seizure
Focal weakness
Headache
Endocrine and metabolic
Metabolic symptoms
Hypoglycemia symptoms
Polyuria
Polydipsia
Skin and extremities
Cold injury symptoms
Numbness
Pain on rewarming
Color change
Blistering
Collateral History and Family History
Collateral source
Collateral reliability
EMS report
Family or bystander
Shelter staff
Police report
Family history
Relevant inherited risk
Sudden cardiac death
Long QT syndrome
Coagulopathy
Thyroid disease
Risk Factors
Patient factors
Reduced heat production and impaired responses
Older age
Frailty
Malnutrition
Hypothyroidism
Adrenal insufficiency
Hypoglycemia risk
Sepsis risk
Neurologic impairment
Environmental and social factors
Exposure risk
Homelessness
Inadequate heating
Outdoor occupation
Water sports
Winter travel
Coagulopathy and bleeding risk
Bleeding risk relevant to frostbite thrombolysis
Anticoagulant use
Recent surgery
Active bleeding
Differential Diagnosis
Life threatening
Cannot miss diagnoses
Accidental hypothermia (T68)
Exposure history
Low core temperature
Hypothermic cardiac arrest
No pulse
Very low core temperature
Sepsis (A41.9)
Infection symptoms
Lactate elevation
Hypoglycemia (E16.2)
Low point of care glucose
Altered mental status
Trauma with exposure
Bleeding risk
Mechanism or injuries
Toxic ingestion
Sedatives
Ethanol
Carbon monoxide exposure
Common
Likely diagnoses
Mild hypothermia
Shivering present
Stable hemodynamics
Moderate hypothermia
Shivering reduced
Confusion
Frostbite (T33 to T34)
Distal numbness
Blisters after rewarming
Nonfreezing cold injury
Immersion or wet cold
Persistent numbness pain
Less common
Zebras and mimics
Myxedema coma (E03.5)
Hypothermia with bradycardia
Hyponatremia
Adrenal crisis (E27.2)
Hypotension
Hyperkalemia
CNS lesion
Focal deficits
Persistent depressed consciousness
Wernicke encephalopathy (E51.2)
Ataxia
Ophthalmoplegia
Past Medical History
Comorbidities affecting risk and management
Chronic conditions
Coronary artery disease (I25.10)
Heart failure (I50.9)
Chronic kidney disease (N18.9)
Diabetes mellitus (E11.9)
Hypothyroidism (E03.9)
Adrenal insufficiency (E27.40)
Seizure disorder (G40.909)
Procedures and devices
Relevant history
Pacemaker or ICD
Dialysis access
Recent surgery
Physical Exam
Initial survey and vitals
Global assessment
Airway protection
Work of breathing
Perfusion
Mental status
Wet clothing and environmental debris
Temperature measurement quality
Peripheral thermometer limitations
Need for core temperature if moderate or severe suspected
General appearance
Severity clues
Shivering intensity
Apathy or confusion
Dysarthria
Ataxia
Cardiovascular
Hemodynamic findings
Bradycardia expected with hypothermia
Hypotension
Irregular rhythm
Peripheral vasoconstriction
Respiratory
Ventilation and oxygenation
Bradypnea
Hypoventilation
Aspiration risk
Neurologic
Neuro exam focus
GCS trend
Pupils
Focal deficits
Tremor versus seizure
Skin and extremities
Cold injury exam
Frostbite staging appearance
Color changes
Sensation
Capillary refill unreliable
Blisters after rewarming
Trauma survey
If unclear circumstances
Head injury signs
Spine tenderness
Long bone injury
Lab Studies
Core hypothermia and complications panel
Initial labs
Point of care glucose
CBC
Electrolytes
Creatinine
Magnesium
Phosphate
Calcium
Venous blood gas
Lactate
Rhabdomyolysis and exposure complications
Muscle injury assessment
Creatine kinase
Urinalysis for myoglobin
Coagulation and bleeding risk
Coagulation testing
INR
PTT
Fibrinogen
Infection and endocrine considerations
If clinically indicated
Blood cultures
TSH
Free T4
Random cortisol
Toxicology
Exposure screening when indicated
Ethanol level
Urine drug screen
Carboxyhemoglobin if exposure risk
Imaging
Scoring Systems
Decision tools for severity and advanced rewarming
Swiss staging system
Stage I
Stage II
Stage III
Stage IV
HOPE score for hypothermic cardiac arrest
Use when considering extracorporeal life support
Not for normothermic cardiac arrest
MRI
Limited role in acute hypothermia
CNS pathology evaluation after stabilization
Contraindications
Hemodynamic instability
Implanted device limitations
CT
Trauma and alternate diagnosis evaluation
CT head if altered mental status with unclear cause
CT trauma imaging if mechanism or exam suggests injury
Contrast considerations
Renal function review
Hypothermia related coagulopathy bleeding risk not a contrast contraindication
Ultrasound
POCUS in hypothermia
Cardiac activity assessment in arrest
Volume status support
FAST exam if trauma suspected
Special Tests
Temperature measurement
Core temperature methods
Esophageal probe
Bladder probe
Rectal probe
Tympanic limitations
Frostbite assessment aids
Cold injury evaluation tools
Photographic documentation for progression
Neurovascular checks trend
Carbon monoxide testing
When exposure risk present
Carboxyhemoglobin
Pulse oximetry limitations
ECG
Key ECG patterns in hypothermia
Hypothermia ECG findings
Osborn waves
Bradycardia
Prolonged PR
Prolonged QRS
Prolonged QT
High risk rhythms and monitoring
Arrhythmia risk
Atrial fibrillation common and often resolves with rewarming
Ventricular arrhythmia risk increases with core temperature reduction
Gentle handling to reduce precipitated VF risk
Serial ECG logic
Repeat ECG triggers
Chest pain
Rising troponin
Significant electrolyte shift during rewarming
Assessment
Severity stratification
Hypothermia severity by core temperature
Mild
32 C to 35 C
Shivering present
Moderate
28 C to 32 C
Shivering reduced or absent
Severe
Less than 28 C
Altered mental status
High arrhythmia risk
Local cold injury assessment
Cold injury category
Frostbite (T33 to T34)
Clear hemorrhagic blisters suggest deep injury
Early appearance may underestimate depth
Nonfreezing cold injury
Prolonged wet cold exposure
Persistent neuropathic pain
Complications to rule out
High risk complications
Hypoglycemia
Rhabdomyolysis
Acute kidney injury
Coagulopathy
Dysrhythmia
Aspiration pneumonia
Trauma occult bleeding
Plan
First 5 minutes
Immediate stabilization workflow
Cardiac monitor
Core temperature measurement if moderate or severe suspected
Oxygen for hypoxemia
Two large bore IV access
Point of care glucose with immediate correction if low
Remove wet clothing
Insulation and active external warming initiation if not severe
Rewarming strategy selection
Rewarming approach by severity
Mild hypothermia
Passive external rewarming
Warm environment
Warm oral fluids if alert and low aspiration risk
Moderate hypothermia
Active external rewarming
Forced air warming blanket
Warm IV fluids
Active core rewarming options if not improving
Severe hypothermia
Active core rewarming
Warm humidified oxygen
Warm IV fluids
Consider extracorporeal rewarming if instability
Hypothermic cardiac arrest modifications
Resuscitation principles
Continue CPR until rewarmed
Defibrillation attempts
Up to 3 shocks if VF or pulseless VT
Additional shocks after core temperature rises
Medication dosing modifications
Withhold vasoactive drugs if core temperature less than 30 C local protocol dependent
Dose interval extension if core temperature 30 C to 35 C local protocol dependent
Extracorporeal life support consideration
Persistent arrest with potentially reversible hypothermia
Use HOPE score if available
Fluids and electrolytes
Perfusion support and metabolic correction
Warm isotonic crystalloid
Hypoglycemia correction
Dextrose IV
Repeat glucose checks
Electrolyte correction caution
Potassium shifts during rewarming
Avoid overly rapid correction without trend
Frostbite and local cold injury treatment
Frostbite management essentials
Rapid rewarming in circulating water 37 C to 39 C if refreezing risk absent
Avoid refreezing after rewarming
Analgesia
Ibuprofen dosing
400 mg to 600 mg PO every 6 hours
Maximum 2400 mg per day
Blister management local protocol dependent
Tetanus update if indicated
Thrombolysis consideration for deep frostbite local protocol dependent
Early presentation within hours
Bleeding risk assessment
Do not do items
Harm avoidance
No rubbing or massage of frostbitten tissue
No dry heat directly on numb tissue
No refreezing after thaw
Avoid rough handling of severe hypothermia patient
Monitoring and reassessment loop
Trend based reassessment
Core temperature every 15 to 30 minutes until stable
ECG rhythm continuous
Vital signs every 5 to 15 minutes if moderate or severe
Glucose recheck every 30 to 60 minutes if corrected
Electrolytes and acid base repeat based on severity and rewarming rate
Disposition
ICU criteria
Intensive care indications
Core temperature less than 28 C
Hemodynamic instability
Ventricular arrhythmia
Need for active core rewarming
Altered mental status with airway risk
Significant acidosis with shock
Inpatient admission criteria
Ward admission indications
Moderate hypothermia after initial stabilization
Persistent electrolyte derangement
Rhabdomyolysis
Acute kidney injury
Pneumonia or aspiration concern
Significant frostbite requiring specialty care
Observation pathway criteria
Observation candidates
Mild hypothermia resolved with rewarming
Normal mental status after warming
Stable vitals
Reliable follow up and safe housing
Transfer criteria
Higher level of care needs
Extracorporeal rewarming capability needed
Deep frostbite requiring thrombolysis pathway
Burn or hand surgery availability for severe frostbite
Discharge criteria
Safe discharge requirements
Core temperature stable and normal
Normal mentation at baseline
Ambulatory at baseline
No evolving ECG abnormality
No significant lab abnormality requiring monitoring
Safe environment with heat access
Discharge Instructions
Copy discharge instructions
Hypothermia and cold exposure
Your body temperature dropped too low due to cold exposure
You were treated with warming and monitoring
Home care
Keep warm indoors
Remove wet clothing promptly if exposed again
Drink warm fluids if you can swallow safely
Skin and frostbite care
Protect numb or injured skin from heat and pressure
Do not rub injured areas
Keep blisters intact unless instructed otherwise
Medicines
Use acetaminophen for pain as directed on the label
If prescribed ibuprofen follow the dosing plan provided
Follow up
Primary care within 1 to 3 days if ongoing symptoms
Specialty follow up if frostbite or persistent numbness
Return to the emergency department now if
New confusion
Fainting
Chest pain
Trouble breathing
Worsening pain
Increasing swelling
Skin turns blue or black
Fever
References
Guidelines and key resources
Evidence sources
Wilderness Medical Society practice guidelines for the out of hospital evaluation and treatment of accidental hypothermia 2019
Wilderness Medical Society clinical practice guidelines for frostbite 2019
European Resuscitation Council guidelines for resuscitation special circumstances hypothermia 2021
American Heart Association guidelines update for CPR and ECC special circumstances hypothermia 2020
HOPE score development and validation for hypothermic cardiac arrest ECLS selection 2016
Project instructions file
Evidence based clinical reference generator
SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.