Have never ever fainted until a fairly important event last year (fortunately not during a crucial moment). At the time, did nothing because I attributed it to the heat, little food and a glass of fizz.
Nearly fainted again last night (tunnel vision, tinnitus, sweats, dizziness) but I sat down in time and managed to pull it back. I then went outside into the cold and nearly fainted again so had to sit down. Had cola and some nuts my friend had in her bag, and it took a while to get out of it. Again, it's probably because it was hot, I didn't eat much and had a pint.
I know fainting is pretty common and I think I know the contributing factors, as I've mentioned above - would you bother going to see a GP in this situation?