Togusa nods, before he clears off the image, so he visibly gives Al a thumbs up to show he approves of the idea. He can shine his flashlight on the ice, enough to see where the vials are, so he gestures for Al to come closer. He'll guide him close enough that the heat will start to melt the surface, but no closer.

Once the ice starts to melt, Togusa will go to work with his own knife, able to slice through the ice with far less sound as it softens from the heat. It will be incredibly slow, but worth it, to him. It's as if his breath, even, wants to slow and quiet, while his ears are primed for a single noise outside.