What does it feel like when scalding hot splashes on the back? (2:13)

He knelt in front of me, waiting, his heavy and turbid breathing like carrying sparks. When emotions piled up to a high point, streams of scalding hot splashes on the back, he felt his spine was like a fuse being lit, the heat spreading from his waist all the way to his nape.
He dared not look back, the air became viscous at that moment, every inch of pore trembled and contracted under that scorching breath, finally succumbing to this silent invasion.