I have always done well with any and all blood work, gave blood before doing double reds and was always been fine afterwards.. However today I went for the bloodwork for #4 and with 6 vials drawn and 2 left to go, I got super hot and couldn't decide if I needed to pass out or throw up.. So they had me lie down with my legs up and turned a fan on, I felt instantly better but it was super weird that has never happened before.