What are the management strategies for hypothermia (low body temperature)?

Hypothermia Management

Manage hypothermia using a severity-based algorithm: passive rewarming for mild cases (32-35°C), active external rewarming for moderate cases (28-32°C), and active core rewarming for severe cases (<28°C), with all interventions targeting a core temperature of 36°C while stopping at 37°C to avoid poor outcomes. 1, 2

Immediate Universal Interventions (All Severity Levels)

Regardless of hypothermia severity, immediately implement these foundational measures:

• Remove all wet clothing to prevent ongoing heat loss 2, 3
• Move the patient to a warm environment and shield from wind 1
• Insulate from cold ground surfaces 1
• Cover the head and neck, as these are major sources of heat loss 1, 2
• Handle the patient gently throughout all interventions to avoid triggering ventricular fibrillation, particularly in severe cases 2

Severity-Based Treatment Algorithm

Mild Hypothermia (32-35°C)

• Use passive rewarming with dry insulating blankets 1, 3
• Increase environmental temperature 1
• Provide high-calorie foods or warm drinks only if the patient is alert and able to swallow 1
• Monitor continuously for signs of deterioration 1

Moderate Hypothermia (28-32°C)

Continue all mild hypothermia measures, then add:

• Apply forced warm air blankets (such as Bair Hugger systems) 2, 3
• Use heating pads and radiant heaters for active external rewarming 3
• Administer warmed intravenous fluids 1, 2
• Provide humidified, warmed oxygen 1, 2

Severe Hypothermia (<28°C)

Continue all moderate hypothermia measures, then add:

• Activate the emergency response system immediately 1
• Implement active core rewarming methods including warmed IV fluids and heated humidified oxygen 1, 3
• Consider peritoneal lavage with warmed fluids for profound hypothermia 3
• For refractory cases with core temperatures around 25°C or lower, consider extracorporeal rewarming methods such as venovenous hemofiltration or cardiopulmonary bypass 4, 5
• Monitor core temperature every 5 minutes during active rewarming 2

Critical Rewarming Targets and Endpoints

• Target a minimum core temperature of 36°C before considering the patient stable or transferring between units 1, 2, 3
• Cease all rewarming interventions once core temperature reaches 37°C, as higher temperatures are associated with poor outcomes 1, 2, 3

Essential Monitoring During Rewarming

• Assess core temperature every 5-15 minutes depending on severity (every 5 minutes for severe cases) 1, 2
• Monitor continuously for cardiac arrhythmias, which can be triggered by rewarming or patient movement 1, 2
• Watch for coagulopathy development during the rewarming process 1
• Assess for rewarming shock, characterized by hypotension as peripheral vasodilation occurs 1
• Check for burns from improper use of active external rewarming devices 1

Laboratory Evaluation

• Obtain cortisol levels to assess for adrenal insufficiency as an underlying cause 1
• Monitor lactate levels and pH, as elevated lactate and acidosis predict poor outcomes, particularly in patients requiring cardiopulmonary resuscitation 6

Common Pitfalls to Avoid

• Do not overlook hypothermia during initial resuscitation—it is frequently missed and becomes progressively harder to treat as more heat is lost 3
• Do not delay rewarming interventions—implement Level 1 strategies (removing wet clothing, applying blankets) immediately in the prehospital setting, even without core temperature measurement 3
• Do not rewarm beyond 37°C—hyperthermia during recovery worsens outcomes 1, 2
• Do not handle severe hypothermia patients roughly—this can precipitate fatal arrhythmias 2

Evidence on Rewarming Effectiveness

• Forced-air warming systems can successfully rewarm patients with severe hypothermia (temperatures below 30°C) at rates of 0.7-3.4°C per hour without causing afterdrop phenomenon 6
• Shivering can increase rewarming rates up to 3.6°C per hour 3
• Early prehospital hypothermia protocols reduce hypothermia incidence from 19% to 3% 3
• Patients without prehospital cardiac arrest have excellent outcomes with appropriate rewarming, while those requiring prehospital CPR have poor prognosis due to irreversible ischemic brain damage rather than the rewarming method used 6