죽은 놈의 콧김만도 못하다 -- Colder than the breath of a dead man.

This expression is used when a fire is going out and its warmth fades away. Alternatively it is used as a criticism for when it is so cold it feels like there is no warmth at all. (불이 사그라져서 따뜻한 기운이 없음을 비유적으로 이르는 말. 썰렁하여 도무지 따뜻함이 없음을 비난조로 이르는 말.)

[edit] See also

• 죽다: to die
• 놈: a person
• 콧김: a snort from the nose
• 못하다 to be worse than