That's awesome! I like giving blood. Last time was about four
  years ago. Here in the USA we get orange juice and cookies,
  sometimes crackers. Usually I wouldn't get woozy towards the end
  but sometimes I would. Didn't matter. It was worth it, and I
  love the idea that my body is going to make a fresh batch of
  blood for me. Plus.. even though 'blood letting" (getting the
  "bad blood" out) isn't a current medical science "thing",
  there's a little bit of me that believes our body is kinda like
  a car engine with the oil.. and maybe there's a little gunk that
  can come out once in a while. Mostly I like that someone else
  can be helped by me. Something of me is going to flow in someone
  else's body. I find that really awesome.