A material with a texture close to human skin is used.
2
noun
body warmth; warmth of the skin
The natural warmth of a person's body. Commonly used in expressions like 人肌の温もり (the warmth of human skin) or when describing temperature, e.g., 人肌程度 (about body temperature).
赤ちゃんは人肌の温もりを感じると安心する。
Babies feel secure when they sense the warmth of human skin.