The tendency to lose one's sense of location and direction in a nonlinear document. The cognitive overhead problem is more related to the user's browsing strategy. It is about how users seek a balance between the gains of added knowledge and the looses from increased distraction by following a link. This limits user's browsing and organization capabilities. The fundamental mechanism for organization is composition.
Some systems allow another window to be opened for the new document.
Browsers simply rely on the window manager to organize these open documents.