The Stovebolt Site Forums The Shop Area Engine Shop Running an engine without exhaust....Risky?

Have never ran an engine without at least the exhaust manifold bolted to the head but I've ran a many of them with just the headers.
...my two cents is some one, years ago, maybe on the artic circle, fired up and engine without even headers bolted to and when it shut off the cold air tighten up the valves