A Heated Combination is an achievement in Deus Ex: Mankind Divided.
This achievement is missable and only available when you are in the prologue mission Black Market Buy. To have another chance at it, you must create a fresh save file.
Proceed forward through Black Market Buy until you reach the first room with a keypad. Just after you break through the first wall.
Turn on the generator in the nearby room. Climb out of the room using the walkway overhead.
And then return to the keypad.
With the keypad now powered, enter the combination 0451 on it. This will grant access through to the next room and unlock the achievement/trophy.