“Coming in hot”

I was getting blood drawn (the yearly doctor’s visit) and the nurse used this expression with reference to an upcoming birthday: “It’s coming in hot!”

I had to ask: is that a midwesternism? A downstate Illinoism? I had never heard it before.

Obligatory sequel: You’ve never heard that before? No. And how long have you lived here? Thirty-four years. And you’ve never? No, never. And where are you from originally? The garden spot of the world, Brooklyn, USA. But really, I just said “Brooklyn, New York.”

The nurse understood “coming in hot” to mean “coming up quickly,” “coming up soon.” She didn’t know where the expression comes from. But she mentioned that she and her co-workers use the expression in a different way when there’s a urine sample waiting to be picked up. You know how there’s a little shelf when you? Yes, I do.

Unlike a birthday, that sample would literally be coming in hot.

[A Quora page suggests that “coming in hot” has a military origin. “The garden spot of the world, Brooklyn, USA”: as per Ed Norton, The Honeymooners. But that expression goes far back.]