Minecraft freezing and not responding, at all.

I was playing minecraft (obviously), doing nothing in particular, just walking, when something takes my attention of my laptop for five minutes, when I return to the game, it is frozen in place. Nothing is happening, and I can't close minecraft, nor can I tab out. The only way to fix it is to reboot my laptop. This has happened five or so times tonight, is there anyone that can help me?