Not really immune but I make sure to drink a glass of water while I take shots and then one per bear at the end of the night. And if I know I am going to drink I usualy drink a bunch of water during the day. Then right before bed I toss back two large glasses of water and asprin..... always seem to be fine in the morning after that
But if I don't do that its 50/50 chance that I get a hang over it seems