Overview
Clinical Meaning
Hypothermia (core temperature <35°C/95°F) slows all enzymatic reactions and cellular metabolic processes.
WHNP
WHNP
Hypothermia (core temperature <35°C/95°F) slows all enzymatic reactions and cellular metabolic processes. Classification: Mild (32-35°C) - shivering thermogenesis active, tachycardia, vasoconstriction, impaired judgment. Moderate (28-32°C) - shivering ceases, consciousness decreases, bradycardia, atrial fibrillation common, J-waves (Osborn waves) appear on ECG at the junction of QRS and ST segment. Severe (<28°C) - loss of consciousness, VF threshold markedly reduced, risk of VF with minimal stimulation (rough handling, central line placement, pacing). At core temperature <30°C, the myocardium becomes extremely irritable: any mechanical stimulation can trigger VF, and the cold myocardium is refractory to defibrillation and ACLS medications (epinephrine, amiodarone have prolonged metabolism and may accumulate to toxic levels). The classic teaching: 'No one is dead until they are warm and dead' - cases of full neurological recovery after prolonged cardiac arrest in hypothermia (especially cold water submersion) are well-documented.
Unlock full lesson + practice questions
4 more sections with scenarios, priorities, and review drills.
Final rapid review before practice
Next study step
Finish the lesson first, then choose a focused activity to apply what you just reviewed.
Continue studying
Sign in to save progress on this lesson.
Unlock the interactive lesson quiz with a plan that includes this WHNP pathway. You can still explore topic-filtered questions from the bank hubs below.