I actually did get seriously ill in South Africa. I was pregnant and began to miscarry on the day I arrived in Joburg. I went to the ER, twice, then was seen by a gyn/ob who diagnosed the end of the pregnancy. I was admitted to the hospital overnight and had a D&C the next morning, then was released.

I paid everything up front with my Visa credit card, got receipts for everything, then submitted the receipts and currency conversion rates to my insurance company. My own insurance company paid promptly, probably because the total cost of care in South Africa was a fraction of what it would have been in the United States. ($839 vs $4-5k in the US)

The lady in the bed next to me told me she was a South African citizen, but living in Virginia, USA. She actually traveled back to South Africa for her hysterectomy because the cost of medical care was so much lower. She could stay with her parents during the recovery period, then return to Virginia.

Some years later, I came down with severe tonsillitis in Germany. I saw the doctor, paid with my Visa card, and again submitted the paperwork to my insurance company back home. I was reimbursed promptly.

In both countries, South Africa and Germany, I was impressed at how quickly I was seen and by the high standard of care I received. The German doctor was great, and all the doctors and nurses I saw in South Africa were wonderful.

ETA: I'll note that this wasn't some "friend of a friend". It happened to me, Yours Truly.