HEART-RATE RESPONSE TO INDUSTRIAL WORK AT DIFFERENT OUTDOOR TEMPERATURES WITH OR WITHOUT TEMPERATURE CONTROL-SYSTEM AT THE PLANT

Different outdoor temperatures, the association between indoor tempera ture control at the workplace and working heart rates of industrial em ployees were evaluated. The subjects, 6,016 male and female employees in 21 industrial plants in Israel, were screened for cardiovascular ri sk factors between 1985-87 (The CORDIS Study). The data collected incl uded resting heart rate, working heart rate (based on one hour ambulat ory EGG), outdoor temperatures, temperature control (TC) status of the plant, workload, age and health-related habits. At outdoor temperatur es below or above 22-28 degrees C, subjects working in plants with TC had lower mean working heart rate HR (-2 bpm) than those working in pl ants without TC (p < 0.0004 after adjustment for confounders). No stat istically significant differences in mean working HR were found betwee n subjects working with TC (at all the outdoor temperatures) and those without TC within the outdoor temperature range 22-28 degrees C. Base d on working heart rate, indoor temperature control in industrial plan ts appears to moderate the cardiovascular strain in working subjects d uring both cold and hot days.