Twice now when in MEXICO in May and June I have had episodes of unprovoked vomiting. I have been going to Mexico for 16 years and have never had any problem, UNTIL the last two times I had to go in May and June. I know these are two of the warmest months so I hydrate myself well, and use precautions such as sunscreen, hats, sunglasses and cool clothing. I never drink alcohol. This time I cooked almost all of my own food (mac and cheese from a box and pasta) No fresh food or unpurified water and I still got sick. I have no symptoms until my stomach starts to turn and the vomiting starts; almost always in the evening; fortunately it is brief, and I go to bed in air conditioning, and hope it doesn't affect me the next day. Some times I get sick; sometimes not. Help...my family is irritated with me.