Windows can be especially dangerous for small children if they are left open or can be opened by a child. The first step in childproofing windows is to remove or rearrange furniture and other objects that a child might climb to gain access to a window. Of course, if a child has the will to get up to a window, there’s probably a way he or she will figure it out. So, you will have to limit the window’s opening size or create a barrier to prevent your child from falling out.
Read full article at Baby-Safe.net: Childproofing Windows