Which type of body temperature is most indicative of Yang deficiency?

Yang deficiency is characterized by a lack of warmth and energy in the body, which can lead to a range of symptoms, including cold sensations and a lower body temperature. When the body is deficient in Yang energy, it often feels cool to the touch, as the Yang aspect is responsible for warmth and metabolic activity. This cooling effect can result in a preference for warmth and a tendency towards symptoms like fatigue and lethargy.

In contrast, feverish body temperature indicates an excess condition rather than a deficiency. Normal and stable temperatures reflect balance but do not specifically highlight Yang deficiency. Warm and moist skin may suggest a state of excess heat or a balanced condition, further distancing itself from the concept of Yang deficiency. Thus, cool to the touch serves as a clear indicator of reduced Yang energy and aligns with the classical understanding of how Yang deficiency manifests in terms of body temperature.