Bottom
灬 — the four-dot fire radical, bottom-form of
火, the indexing radical. Adds a second light source under the
日 sun above: 'sunlight on top, firelight below.' Pictures double illumination, making
照 emphatically about light and shining. Same
灬 family:
热 hot,
烈 fierce,
煮 boil,
然 (originally to burn).