That'll be a cold day in hell.
→죽었다 깨도 그런일은 없을꺼야.

〔예문〕
A:Honey, I think I'll quit someking.
  여보 담배를 끊어야겠어.

B:You quit smoking? That'll be a cold day in hell.
  끊는다고요? 말도 안돼.

A:I mean it. I'm serious this time.
  진짜야. 이번엔 심각하다니까.