To be cold-blooded. Usually a phrase type used in sports when you're clutch under pressure and you rise against adversity.
When the game is on the line you gotta have ice in your veins.

Kobe Bryant has ice in his veins. He shows no mercy against his opponent when the game is on the line when he slashes through players with killer instinct.
by Sivraj85 February 15, 2012
Get the Ice in your veins mug.