Hypothermia

Definition

Hypothermia is a core body temperature less than 95°F (35°C). It progresses through mild (90 to 95°F), moderate (82 to 90°F), and severe (less than 82°F) stages with increasing risk of cardiac arrest.

Causes

• Environmental exposure
• Immersion in cold water
• Trauma and immobility in cold
• Post-op (anesthesia, cold OR)
• Sepsis, endocrine (hypothyroid, adrenal insufficiency)
• Massive transfusion without warming

Signs and Symptoms

Shivering (absent at greater than 90°F mild; ominous sign), confusion, slurred speech, bradycardia, hypotension, arrhythmias (Osborn J waves on ECG), coma.

Rewarming Strategies

• Mild: Passive external, such as remove wet clothing, blankets, warm environment.
• Moderate: Active external, such as forced-air blankets, warm packs.
• Severe: Active internal, such as warm IV fluids, warm humidified oxygen, lavage, ECMO.

Nursing Considerations

Handle gently (ventricular fibrillation risk), continuous cardiac monitoring, rewarm slowly (1 to 2°F/hour). 'Not dead until warm and dead'. Prolonged resuscitation indicated.

NCLEX Relevance

Slow rewarming; gentle handling. Classic: 'Not dead until warm and dead.'