Hypothermia develops when the body temperature is below ______ .

Appeared in: UP CHO - 10 September 2021

Explanation

Hypothermia is clinically defined as a core body temperature that falls below 35°C (95°F).
This temperature is the threshold at which the body's normal metabolic and physiological functions begin to be impaired by the cold.
While lower temperatures signify more severe stages of hypothermia, the condition officially begins at 35°C.

Option A: A body temperature of 45°C is extremely high and constitutes severe hyperpyrexia (a very high fever), which is the opposite of hypothermia. It is a life-threatening condition that can cause brain damage and death.
Option B: A body temperature of 30°C indicates moderate to severe hypothermia, not the initial point of onset. At this temperature, shivering often stops, and the patient's level of consciousness is significantly impaired.
Option D: A body temperature of 20°C represents profound, life-threatening hypothermia. At this stage, the patient is typically in a coma, and there is a maximum risk of cardiac arrest (asystole or ventricular fibrillation).

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Definition and Temperature Threshold for Hypothermia as background academic context rather than a clinical decision trigger.
Accurate diagnosis is critical. Nurses should use a core thermometer (rectal or esophageal) as peripheral thermometers are unreliable in cold patients.
During rewarming, it's crucial to handle the patient gently. Rough movement can trigger ventricular fibrillation, a fatal cardiac arrhythmia, in a cold, irritable heart.
Core temperature afterdrop is a phenomenon where the core temperature continues to fall even after rewarming has begun. This happens when cold blood from the extremities returns to the core. Continuous monitoring is essential.

How to Approach the Question

Identify the key term in the question: 'Hypothermia'.
Recall the standard medical definition for the onset of hypothermia.
Scan the options for the temperature value that matches this definition.
35°C (95°F) is the internationally recognized threshold for hypothermia.
Eliminate other options: 45°C is hyperthermia, while 30°C and 20°C represent more severe stages of hypothermia, not the initial threshold.

Concept Tested & Keywords

QoRPeuYn82zAS20UaW3_JI

E6 Nelson Textbook of Pediatrics(2024) — Volume 1 pp. 684-686, 703-705

E6 Physiology Essentials Sembulingam 10e Part 2 p. 11-13

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