It's a bummer. I tried to donate blood today but was foiled when the blood refused to flow out of my vein. This hadn't happened to me before. I was very well hydrated, having drank nearly a gallon (six 20oz containers) of tea/coffee & water today before trying to donate (not to mention eating 8lbs of water rich fruits & veggies this morning).
I think it was likely a result of my recent experimentation with intentional cold exposure (documented ad nauseum here), and being chilly (especially my hands) when I went to donate. I didn't feel unusually cold, but I think I've gotten used to it. My oral temperature was low (97.2 °F), but not terribly so.
I know Michael has trouble even getting a drop of blood out for a glucose test. Anybody else have trouble bleeding?
--Dean