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 condi­tioning units. Only the dock areas, win­dowed offices, and lunchroom have heat­ing and air conditioning units, and even they have only one-fourth the units that a conventional building would need. De­spite this, the temperature in the ware­house stays about 70° F (21 ° C) year round. How is this possible?