“Up from the mouth of each hole there stuck out a sinner’s feet and legs up to the calf, the rest of him remained stuffed down inside. The soles of both feet blazed all on fire. The leg-joints wriggled uncontrollably and would have snapped any rope or tether. Just as a flame on anything that’s oily spreads only on the object’s outer surface, so did this fire move from heel to toe…”
The Divine Comedy (1320), Inferno: Canto 19 – Dante Alighieri