I do this one. "Double reds" they call it--taking out 2 units of red cells. Basically, they take a pint, centrifuge it, pump the plasma and some saline back into you, take another pint, do the same. It can give you a very weird feeling as the plasma goes back in. I would not recommend it for someone who is uncomfortable with donating blood, for any reason. Especially Pyrrho. And it takes roughly twice as long to do.
I finally tried the "Double Reds" proceedure last night. "Very weird feeling" doesn't even come close to decscribing it, but I will never go back to giving it the old way again.
There was only one needle stick, which I was very pleasently surprised to find out. I did start to slip into shock almost immediately, but after the first time they pumped it back into me, I was fine.
The weird feeling is very hard to describe. For me, it was like laying on top of a very quiet washing machine. First my arm and then my whole trunk would vibrate slightly. They put an anti-coagulant in the blood for storage and some of that gets back to you. That makes your lips, tongue and gums feel tingley, like they are asleep, but without the numbness.
The strangest part, by far, was the cold. Normally, when you get cold, you feel it in your extremities first. It isn't until it gets down into the main part of your body that you start shivering. The stuff they pump back into you is about room temperature (20-30 degrees cooler than body temp) and goes almost straight into your body core. So, I started shivering after a few minutes, but every other temperature indication I had told me that I was comfortable. My legs and non-donating arm was warm and comfey. It took me a good 20 minutes for my chest and back to stop shivering, even though I felt fine otherwise.
I can't tell you how strange it is have an involuntary "must get warm" impulse when, if anything, I was a little hot.