The aim of this study was to find out the effectiveness of equipment used to prevent cold air flows in the wind boxes of commercial buildings and super markets. Measurements were carried out in 14 buildings at the total of 42 work sites. The effectiveness of the equipment used to prevent cold air flows in wind boxes was insufficient. The measurements showed that temperature changes and air flows can reach even beyond than 10 m from the wind box and create serious local draft at work sites. Two things which should be emphasized in future are: first, new more effective air technologies should be developed for preventing draft in wind boxes, and secondly, the traffic density through the wind box, the location of the work site, the protectiveness of clothing, and the nature of the work should be taken into account when thermal conditions are measured or when draft prevention is designed.