Do my emergency exit windows open?

What you appear, from the photo, to have is a regular sliding window that is large enough to be designated as a fire escape .. Thus the red handle. So if that's the case, of course , yes use it. You should open all your fire escape windows once in awhile to make sure they aren't stuck from age and to insure you understand how they work. Many swing out on a hinge just leaving the outside frame and as previously said the rubber seal can stick.