A unique experience

But one that I do not wish to repeat in the near future.

I was sitting here at the computer, minding my own business, when I started to feel a little queasy. Then a lot queasy. I decided to go into the bathroom and splash water on my face, whereupon in the space of two minutes I felt very queasy indeed, started to sweat uncontrollably, lost most of my hearing and nearly all vision, lost the ability to stand up straight and finally woke up on the floor.

The reason? I have no bloody idea. But it was interesting while it lasted, if extremely scary. Answers on a postcard please.

PS My head hurts where I smacked it on the wall :o(