Why We Can't Open The Windows Inside A Plane
Keep in mind as well that this all means the windows on airplanes need to be quite strong; that also makes it a problem to make them able to be opened. There are a lot of balances that have to be struck on airplanes to keep them both safe and flyable. Air travel is much more constrained than land travel. Structural strength is a consistent issue on planes.
A fun side note: safety factor on a typical airplane is about 50 percent; in most flying animals it is 200 to 220 percent. That means planes are built to take 50 percent more force than you expect them to actually ever encounter. But birds do crazy stuff. Falcons manage roughly 24g's of deceleration at the end of stoops. That would kill a human. In a g suit. In a top-of-the-line jet fighter.
Inside a plane, one has oxygen masks in case pressure in the cabin is lost. But that doesn't solve the temperature problem. Most commercial airplanes fly even higher than the peak of Everest. In the middle of summer, the peak of Everest is about -20°C or about -4°F (i.e. 36 degrees below freezing) -- and that's on a balmy day. Passengers would enter hypothermia rather quickly -- particularly as they probably aren't flying in Antarctic adventure gear. That's why if there is a loss of the pressure seal, and the masks deploy properly, the pilot needs to get to lower altitude quickly.
Well, that's one reason, at least. Another reason for lowering altitude is that there isn't an unlimited supply of oxygen on board, meaning the masks will eventually run dry. Another reason is that sudden pressure drop can cause some passengers to pass out before they manage to get a mask secure. On the aerodynamics side, if there is some sort of structural emergency, it may be prudent to slow the plane down and the minimum speed is lower where the air is thicker.
There you have it, Mittens – and anyone else who has wondered why we can't roll down the windows in a 747.