Setting a stop loss

[TheUncle]

It also matters whether you lose a buyin due to a really bad beat, or a cooler like set over set; I tend not to get upset about those (just annoyed). I do take a break if I lose two stacks due to dubious calls or otherwise marginal decisions (because it may indicate that I'm not sensing the game dynamics properly). I definitely take a break if I am worried that I'm getting outplayed in big pots.

In any case, some people say they take a 5 minute break whenever they lose a buyin. If that helps you refresh your mind and refocus on your game plan again then that's a good idea.