Treatment of Hypothermia

Classification and Treatment Approach

The American College of Critical Care recommends a tiered approach to treating hypothermia, with passive rewarming for mild cases, active external rewarming for moderate cases, and active internal rewarming for severe hypothermia 1, 2

For mild hypothermia, the treatment approach includes removing wet clothing immediately, increasing environmental temperature, and applying warm blankets 1, 2
For moderate hypothermia, active external rewarming methods such as heating pads, radiant heaters, and forced warm air blankets are recommended, in addition to continuing Level 1 interventions 1, 3
For severe hypothermia, active internal rewarming methods such as administering warmed intravenous fluids and considering peritoneal lavage with warmed fluids are recommended, in addition to continuing Level 1 and 2 interventions 1, 4

The rewarming rate can be increased with shivering, up to 3.6°C/hour, and external rewarming can still be effective in severe cases, with one study showing successful warming of patients with temperatures below 30°C using forced-air warmers 2
The rewarming target should be a minimum core temperature of 36°C before transferring patients between units, and rewarming should cease after reaching 37°C as higher temperatures are associated with poor outcomes 5

Early rewarming in the prehospital setting can reduce hypothermia incidence, and implementing Level 1 strategies immediately, even without core temperature measurement, is recommended 2, 3
Early organized prehospital hypothermia protocols have been shown to reduce hypothermia incidence from 19% to 3% 2

Hypothermia is often overlooked during initial resuscitation, and emphasis should be on prevention first and treatment second, as it becomes increasingly difficult to rewarm patients once significant heat is lost 2

The American College of Critical Care recommends initiating forced-air warming when a patient's core body temperature drops below 36°C, or prophylactically in high-risk surgical cases to prevent hypothermia from developing 6
The American College of Critical Care suggests that temperatures below 34°C compromise blood coagulation, representing a critical threshold where coagulopathy begins to develop 7
The American Heart Association recommends maintaining normothermia (≥36°C) throughout most surgical procedures to prevent complications including myocardial ischemia, coagulopathy, and increased mortality 8
The American Heart Association found that maintaining normothermia reduces perioperative cardiac events by 55% (morbid cardiac events: 1.4% vs 6.3% without warming) in high-risk noncardiac surgery patients 8
Each 1°C decrease in temperature causes a 10% reduction in coagulation factor function, making early intervention critical in trauma and surgical bleeding 7

The American College of Critical Care recommends ceasing rewarming at 37°C, as temperatures above this threshold are associated with poor outcomes and increased mortality 6
The American College of Critical Care suggests targeting a minimum of 36°C before transferring patients between units 6

The American Heart Association recommends avoiding rapid active warming in post-cardiac arrest patients, while maintaining temperature between 32-36°C is recommended 9, 10, 11