How to get rid of a sunburn FAST? How to prevent them from turning into tans?

I am extremely pale. I mean, vampire kind of pale. I absolutely love my pale skin and despise the slightest bit of tanning. Today I went out to Gay Pride and forgot to put on sunblock, and my arms are sunburnt pretty badly. I am furiously putting any kind of lotion I can find on it. How do I get these sunburns to go away within the next week and how do I prevent them from turning into tans?