wool rug
毯 centers on a thick, soft textile made from animal hair: a wool rug or blanket.
毯 combines 毛 (hair, wool) with 炎, which likely contributes the sound タン. The character originally referred to a woolen rug or blanket.
The outer 毛 is wool, and the inner 炎 looks like two fires. Imagine a wool rug so thick and warm it feels like sitting between two cozy fires.
For タン, picture a tan-colored wool rug: tan -> タン, and the rug is made of warm wool.
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