turning to the inter-web for health advice

okay, you seem like a sporty group of people, i'll ask you...

i have had this thing happen to me a couple of times while working out and i'm wondering if anyone knows what it might be (yes, i will talk to my doctor about it, but i'm going to see her relatively soon, so i don't want to make a special appointment for it...)

i will be happily working away and all of a sudden i get quite cold, then my eyesight changes a bit, everything gets extra bright and kind of sparkles (a bit like pre-migrane actually), i feel a tiny bit faint, and i feel like i'm going to maybe throw up.

it's happened to me maybe 3 times now (over the last several months, so, it's not new, it's not frequent, it's just weird)

someone who was there and saw it happen today said my face went white as a sheet and my lips turned blue. i commented that i wondered if it was blood sugar, she gave me her diluted fruit juice to drink, i had that and sat for a minute. when i went to the bathroom my face was almost normal colour, but my lips were still purple. i felt a little shakey for about 5 or 10 minutes, and then i was fine. i mean, i stopped working out, i didn't want to push it, but i was just fine showering and walking to work.

so, now it's your turn to practice your amature doctoring skills and play "diagnose mainja"

some quick facts:
- it has only happened when working out in the morning, never in the afternoon.
- although i don't eat before working out in the morning, i do have a glass of milk when i get up.
- it happens when i'm using weights, not when i'm doing cardio (although it sort of happened once on cardio, but it didn't last and i didn't have to stop)
- there's nothing different about my workouts when this happens, it's not something that happens when i push the weights
- the train left the station at 10am going 120 km/hr

anyone know what the hell is happening to me? i don't even know where to being to do an internet search on this, so i'm hoping that maybe someone knows someone who has had similar experiences and could shed some light on the situation..