Physical stimuli and emotional stress-induced sweat secretions in the human palm and forehead

When sweating is induced by emotional or physical stimuli, the observation of the behavior of active sweat glands and measurement of the sweat rate are useful for the estimation of the degree of emotional stress on humans. When a loud sound was produced behind the subject's head, a periodical damped oscillation of sweating was observed. This sweat secretion may correlate with how a human being absorbs a big surprise stimulus. The differences of the time lag for starting to secrete sweat from sweat glands may correlate with the performance of the nervous system and/or the difference of body condition with and without stress. An intake of caffeine stimulates the central nervous system, and it rises basic, mental and thermal perspiration. The degree of physical stimuli given is amplified by the dose of caffeine, and sweating becomes 1.5–2 times greater compared to that without the dose. This study shows that sweat rate can be used as a good indicator for the state of body conditions.