The time frame could indicate staph food poisoning, which lasts for 2 or 3 days. It'd be hard to find the culprit at this point, though, as that food should already by out of your system. SFP is very commonly caused by bad eggs or dairy (milk, cream, and butter are often to blame), so are you sure it wasn't from breakfast or a morning snack? This would make more sense to me, as the heat could quickly make a pasty or the like an attractive target for bacteria.
If it is this, avoid spicy foods and don't drink alcohol or coffee for a few days (avoid dark sodas as well), that'll help you recover.
I don't want to discount the possibility that Disney might be to blame, but it might also be a skin-borne germ that is to blame. Again, a scorching summer day in Orlando means everyone's sweating and leaving their little friends everywhere.... doorknobs, queue railings, faucets, ride handles, whatever. Forgetting to wash just once before you eat could put them in your system, and depending on your immune system health, whammo....
I hope you feel better in time to enjoy the rest of your vacation, though....