Health
There are excellent, world class medical facilities in cities and larger towns, but in rural areas the clinics and hospitals deal mostly with just primary health needs.
The tap water in most areas of South Africa is drinkable.
In some areas, the water is mineral-rich, and you may experience a bit of gastric distress for a day or two until you get used to it. Bottled mineral water, both sparkling and still, is readily available in most places.
Safety
The crime rate is South Africa is high and, apart from car accidents, it’s the major risk that someone can face in South Africa. This doesn't necessarily apply to tourists though. If you are on an organized tour or with a group, stick to established tourist areas, avoid dangerous places like townships and follow a few common sense rules, it quite safe. Remember that despite the statistics the majority of travelers visit the country without incident and return happy with their journey.
It is recommended that you never walk alone at night, don't wear expensive jewelry, spread your valuables in various places, avoid driving alone, lock your car doors at all times, keep your windows up and be alert to strangers approaching your vehicle when stopping at urban and suburban intersections.