Had a useful email a few weeks ago. If someone collapses inexplicably then come round shortly afterwards, ask them to stick out their tongue - if it falls fo one side chances are they had a stroke. ask them to lift their arms up - if cant do it then chances are a stroke. ask them to put a simple word into a sentence (eg 'sun' - teh sun is not shining), if cant do it then chances are.......... It may not be but (sorry Tom!) would you really want to take the chance?