Depicts a hand (寸) holding two stones over fire (火) to iron a person's (尸) back as a treatment for a disease. Based on the original meaning "to iron", now written as 熨. The current meaning is a phonetic loan.
Shuowen Jiezi
《說文》：“尉，从上案下也。从、又，持火以尉申繒也。”
Original meaning
to iron
Components
尸(iconic) — Depicts a person sitting or squatting.
◎(iconic) — Depicts two pieces of small elliptical stones.