This is something that came to mind reading some of the comments on this post. It's good advice to be aware of our limits and to do something once its become clear that we're being overworked past our limits. How do you know what that limit is? What would have to happen for you to stand up to your boss about your hours, regardless of the potential consequences?
Figured it would be helpful to hear some signs to look for when you're being pushed too far. It's going to be vary a bit based on people's health and experience but I'd like to hear everyone's thoughts.