crouch, hunchback
痀 centers on a physical condition of being bent or curved: a crouching posture or a hunchback. Both meanings describe a body that is not standing straight.
痀 combines 疒 (sickness) with 句, which likely contributes the sound and may suggest a bent or curved shape, fitting the idea of a hunched or crouching body.
The sickness enclosure 疒 wraps around 句, which looks like a person bent over. Picture a sick person crouching with a hunched back inside the enclosure.
For ク, imagine a person crouching in a cool, dark corner: cool -> ク, and the hunched posture fits the cramped space.