People who work in large office buildings get sick more often than normal. They may have headaches, stomachaches, or sore, red skin, The reason or this lies in the buildings themselves. These large buildings usually have windows that cannot be opened. The same air stays in the buildings for a long time and becomes unhealthy. It may be full of chemicals that come from the furniture, the rugs, or the photocopy machines. Or it may be full of cigarette smoke. This unhealthy air causes ’’sick building syndrome.” as doctors call this problem. It order to cure the people with this syndrome, it is necessary to treat the building. The answer is simple : more fresh air.