For anyone who doesn't know what "these hands" are. They allow you to throw punches without a gun in your hands. This way added in one of the most recent patches.

Basically, I'm just wondering if there is a button to press to bring them up or a way to get the condition to get them.

Since there is only [so far to my knowledge] one way to get them. which is in the 2nd level are leaving the lifeboat where "these hands" are seen and as long as MC doesn't pick up a second weapon, you can switch between whatever gun you have and "These hands"

any info will be helpful. Thank you.