I can reach those values by exercising or even constricting muscles (e.g. sphincter) but you wouldn’t say that I’m stressed. Stress as I understand it is a complex state characterized by among others, excess anxiety, increased basal metabolic rate, heightened awareness. Essentially an increase in most dimensions from a basal rest state.
Usually what is really meant by stress is a state of chronic sympathetic arousal / insufficient parasympathetic activation
(I agree that people use the word vaguely and in a lot of different ways)