烫
tàng · HSK 7
to scald
🔥♨️ 汤 (hot soup) over 火 (fire) = water hot enough to scald — 烫
The top is 汤 tāng, hot soup or boiling water; the bottom is 火 huǒ, fire. Boiling-water-plus-fire is what burns you, so 烫 means to scald or blanch. The sound tàng even rhymes with the tāng inside it.
烫 — hot 烫 = 汤 (tāng, soup) + fire 灬
A semantic-phonetic compound. The bottom 灬 (fire) gives the meaning 'hot/scalding,' while the top 汤 (originally 'hot water/soup') supplies the sound tàng. The character thus depicts something heated by fire, extending from 'scalding hot' to verbs like 'to scald' or 'to iron (clothes).'