Transcutaneous partial oxygen tension (tc pO₂) and skin blood flow (via heat clearance) were measured noninvasively in 22 male subjects who performed stress-inducing tasks (i.e. hand-grip exercise, cold pressor test, breath holding, hyperventilation and mirror-tracing). An analysis of variance and covariance was conducted for tc pO₂ heat clearance, heart rate, respiration rate, finger pulse volume and systolic/diastolic blood pressure. Results indicate that tc pO₂ can depict phasic cardiorespiratory challenge. Heat clearance proved to be less sensitive to the demand conditions used here. An analysis of covariance revealed a negative correlation between tc pO₂ and blood pressure and respiration rate, as well as a positive correlation between tc pO₂ and heat clearance. This suggests that phasic changes in tc pO₂ are induced by both peripheral vasomotor activity and changes in arterial pO₂.