Keeping track of your health is a main priority when traveling, aside of course from enjoying the trip. It’s difficult to rush in emergency rooms and picking the hospital to be in when you’re in other countries.
Brazil has some of the best hospitals and generally cost lower than in U.S. and UK. Hospitals in here has no reciprocal deal with other counties so if you get sick in Sao Paulo, you will have to foot your own bill. We suggest that you don’t get sick!
The tap water can be safe in major cities but if you decide to travel further in Sao Paulo, you may have to go for the safer option.