Though built near Chicago, where temperatures plummet below 0° F (-18° C) in the winter and exceed 100° F (38° C) in the summer, the 430,000-square-foot (39,948 m2) warehouse of. Roman Inc. has no heating or air condiÂtioning units. Only the dock areas, winÂdowed offices, and lunchroom have heatÂing and air conditioning units, and even they have only one-fourth the units that a conventional building would need. DeÂspite this, the temperature in the wareÂhouse stays about 70° F (21 ° C) year round. How is this possible?