Will opening a hot kiln to remove raku pieces damage the firebricks?

Electric kilns are generally made with K-23 firebricks, which have a low alumina content. (K-25 bricks have a higher alumina content.) Low-alumina firebricks can withstand dramatic temperature changes without cracking. It's better, of course, to wait until the kiln has cooled to room temperature before opening it. Nevertheless, you can open a hot electric kiln to remove raku pieces without undue damage to the bricks. Glass fusers open the lids of their hot kilns to rake or emboss the surface of the softened glass. You can also fire as rapidly as you want. The K-23 bricks are less susceptible to cracking from rapid firing than any clay you will ever place inside the kiln. The bricks are soft and fragile yet also durable.