Open Windows

It turns out that closed windows in large hospital wards may increase patients’ risk of getting an infection.  Using a tracer gas to simulate how airborne infections spread, researchers of a recent study showed that open windows help ventilation in the ward and lowers the risk of airborne infection. The study in the current online issue of the Building and Environment Journal showed that when the windows were closed the risk of infection increased fourfold.   So, the question is, why aren’t windows able to be opened?   I know the answer but it is a pop quiz for you.