Laying on my back for four hours during the collection was the hardest part. My butt was sore and my arm hurt from holding it in one position for so long. The also gave me an anti-coagulant drug to keep my blood from clogging up the machine. But this drug binds to the calcium in my blood stream which has the effect of making me feel "tingly" in my face and arms. When I got up I was dizzy for about 15 minutes.
The net effect of all this was to put me in a bad mood. In fact, I was grumpy. But as I lay there the last half hour, anxiously awaiting for it to be over, I was reminded of a verse from the Old Testament book of Isaiah:
"But he was pierced for our transgressions...
And by his wounds we are healed." ISAIAH 53:5
This verse describes, centuries before the birth of Jesus, how Christ's suffering and death was for us to be healed, for us to be reconciled to God, and for us to be forgiven. It seemed to me that God was reminding me of his sacrifice for me, and encouraging me that I could "share in his sufferings" in a little way, in order to help someone else be healed. May it be.