When you open a window of a warm room, the air from the colder outside rushes in (you can see the curtains bend into the room, for example). But shouldn't it be the opposite? The higher kinetic energy of the hotter air molecules inside the room should create more pressure than the colder air molecules outside, and so when a window is open the air should move from higher pressure to lower pressure, i.e. from inside to outside. And if the explanation is that the hot air does indeed move to the outside, and the cold air rushes in to fill the created vacuum, why do we feel only the cold air coming in and why is the net force pushing in the inside the room direction?