I also won’t forget my last night in São Paulo having somehow caught some sort of food poisoning. Unfortunately I don’t really have much clue as to what caused it but I never really felt anything like it. We did eat a few small snacks at a bar after my talk, and I had a caipirinha. By the time I got back to hotel, I was shivering a little bit (figuring it was partly because how cool it was in São Paulo and the normal post-drinking effects) but it didn’t really go away, even when I was laying in bed covered up.
I also found I had a lot of stomach gas that I would burp up but never seemingly go-away. I was restless for another hour or two, although the shaking seemed to have got a bit worse where I decided it might be healthier to try to worship the porcelain bowl. Amazingly after that episode, things seemed to clear up. The shaking stopped instantly.
Sorry if you’ve gotten this far and felt I shared a little too many details.