Ever wasted a lot of time doing CSS and trying to fish for an element that disappears just when you click something on the browser inspector? Think styling autocompletes.
Well, after years and years and years suffering through that, I finally decided to Google how to freeze the page and be able to click around the inspector as much as I want without changing the DOM.
Stack Overflow shows 2 or 3 easy ways:
http://stackoverflow.com/questions/17931571/freeze-screen-in-chrome-debugger-devtools-panel-for-popover-inspection