We would follow the pipe, but not turn the valve.

Look at my map. We're currently at the cliff. Going back to the cave would mean that we would be facing it, yes? When we're at the cave entrance, we follow the pipe right, keeping in mind that the positions of the left and right pipes have been reversed.

What kind of 'experimenting' are you proposing?

And Xobim, I think we'll freeze to death if we follow the unheated pipes.