What does Proctor mean when he says, "our old pretense is ripped away gods icy wind will blow"?

Throughout the action in The Crucible, John Proctor struggles with hypocrisy. Although he speaks out against the persecution of the girls accused of witchcraft, he is hiding the affair he had with Abigail. His struggles are with his own conscience and his fear of God. Proctor has to decide if he will confess the sin of adultery, for that might be the only way to save his wife. If, however, he confesses to witchcraft—falsely, as he knows he is not guilty of that—he may save his own life.
In act 2, when he speaks the line quoted, he has been speaking with Mary Warren, who reveals that she knows about the affair. At this point, it seems he has nothing left to lose so he tells Mary “tell the court what you know.” He grabs hold of her, insisting over her fear that she do it: “My wife will never die for me.”
As Mary continues to refuse, he threatens her, saying she must make her peace with the outcome. It is a fight between Heaven and Hell, he says, and they cannot pretend any more. “[W]e are only what we always were, but naked now. Aye! Naked!” By “God’s icy wind will blow” he means the frightening punishment of God will be inflicted on them all for their sinful behavior.