What if a woman offers her hand to shake hands with a muslim man? I'm very worried I'm going to forget and I'm going to do this automatically and inadvertently cause offence.

Are people offended when this happens? Do they say something to rebuke you? Do they shake your hand anyway, so as not to cause offence by rejecting your hand?

What's the best course of action? Wait to see if a man offers to shake your hand? Or would he think you were rude if you meet someone and don't offer to shake their hand?