Compared ambulatory blood pressure (BP) and heart rate (HR) in 30 paramedics during a 24-hr workday and a 24-hr nonworkday. During the 24-hr period as a whole, there were no BP differences between the workday and the nonworkday, but HR was higher during the nonworkday than during the workday. Systolic BP (SBP) recorded in the ambulance on the workday was elevated 9.8 mm Hg, compared to SBP recorded in a car on the nonworkday; it was also 7.2 mm Hg higher at the scene of an accident and at the hospital than during nonworkday activities. Ratings of moods in diaries indicated that paramedics felt more unhappiness, stress, and sadness and less feelings of pleasantness at work than at home. Rather than being elevated for the entire 24-hr period, work BP seemed to reflect the relatively high stress associated with specific situations in the work of a paramedic.