Work destressing

Work has been extremely busy recently. (Mostly in the "I have three high-priority things all to do right now, plus four people wanting attention in person" sort of way.) Ignoring the root causes of this, does the world have any suggestions on things I can do to just calm down? Angsting over how terrible the code is (much of it I wrote, even) or what other people consider crises doesn't really help actually get things done.