Headrushes can cause some embarrassment, because they occur on a slight delay, so that you're already far from your chair when the feeling kicks in. If there's a table or wall nearby, lean on it for support just in case. Otherwise, just sit down or stand there for a few seconds.
If you are prone to skip meals some days, or don't get enough sleep, you are more likely to get headrushes. Frequent headrushes are crazy as hell, but get old pretty quickly.
"Whoa, dude, I just headrushed like crazy. I need to stop playing TFT for a while, I've been on for like three hours."
"No way dude, we don't have enough to get stoned"
"We can still pack a mighty fine head rush though man!"