The last time that happened to me it was at the aeropuerto in Cozemel from an E Coli infection. Worst expereience in my life (well maybe - the cancer Tx kind of sucked but I have put most of that behind me). Actually had to have a Mexican doctor make a house call to our luxury hotel in Cancun. He was good though and cheap compared to American doctors - 50 bucks for the house call and that included the penicillin shots.

Watch out for that tea - it can dehydrate you. Drink lots of water - 2-3 liters/day.

I couldn't handle Boost at all, just the chalky texture of it in my mouth made me want to vomit. I switched to Carnation Instant breakfast, which was milk based and had a lot better luck.