Yeah that's how I feel Neo! Lightheaded and too hot but clammy. If I don't leave the room and sit down somewhere then my vision goes all black and my hearing goes funny. I've never fully passed out though. It's such a weird feeling! That's awesome that you managed to give blood though. My friend does it regularly and I can't even stand her talking about it let alone walking into one of those places! xD I've never had a blood test before, I would definitely not be able to handle it.