Like Marc, I've done shitloads of welding of galvanised steel and often came down with the dreaded 'Gal Lurgi' which has symptoms not unlike the flu. Milk is indeed the best short term 'cure'. One time I came down with a bout of severe headaches, halucinations and nightmares after welding an aftermarket alloy Chev engine block that had been 'dipped' in some sort of cleaning process. I just may have been a similar experience to the above bloke. I was as crook as Rookwood for at least a week but didn't go to the doctors. After reading the above, perhaps I should have. My kidneys aren't in the best of condition today and this may have had something to do with it.
A good warning for all welders.