In official-looking letter, marked Tresor Public, arrived today. It provided the final solution to my question: what happens if you fall seriously ill on holiday?

We all know that if you go somewhere like the United States, which doesn't have a national health service, you need to take out private insurance. We also know that Form E 111 gives you access to the health services of the European Community and most other European countries.

But we tend to think that E 111 makes private insurance unnecessary when visiting Europe. My experience in France last summer however, has convinced me that you need to take out the best private insurance cover you can get.

In July, my son Richard, aged 19, arranged a last-minute holiday with friends in Brittany. He did not take out insurance. Ten days later, he was involved in a serious accident in Carnac and rushed by ambulance to hospital in Auray. When the news reached us, I dropped everything and flew out to his bedside.

That was my first lesson. If you pick up the phone and say you want the next flight to Lorient the fare will not be the usual travel agent price, but pounds 465.

When I arrived, I found that Richard had broken his pelvis in four places but was in good hands. He even had a room of his own and a telephone. But his injuries were very serious, he was suffering a lot of pain and he was in traction. Moreover, he was dependent for everything upon his nurses, who spoke a language he scarcely understood.

Being suddenly transported to this Breton hospital was a strange experience for me. Finding out what had happened, about my son's condition and the prognosis, talking to the local police and social security - things that are difficult enough to do in your own language - were much more difficult in French.

Once all this had been settled by visiting the gendarmerie, the mairie and so forth, the main problem was whether or not to repatriate Richard. Although this was the reason I had flown to France and what Richard desperately wanted, the decision depended on whether or not he needed an operation. If he did, he would have to spend even longer in traction, and it would be better for him to do that in Britain, where his morale would be much higher.

Repatriation would mean hiring an ambulance, and then taking a ferry, chartering a plane or booking a whole bloc of seats, to take him back in traction. In France the ambulance service is quite separate from the medical system, and we were left on our own to make the arrangements.

The British Embassy in Paris gave first-class help. They put us in touch with St John Ambulance Alert, who were also very good. But the cost of returning to Sheffield by boat and ambulance would be at least pounds 2,600, and by air more than pounds 4,200. Though completely without insurance, we were determined to find the money somehow and started to book a passage with St John Ambulance Alert.

But just as we were all set to go, the surgeons decided he did not need an operation, and that his pelvis was healing so well it would be best for him to stay in France. Richard took this very well, and my wife, Mary, and I were left with the cheaper option of living in Auray for two months.

Cheaper, but not exactly cheap. I had to get back to work, but before I left we rented a basement flat on the outskirts of the small town from which Mary could visit him every day. Auray is a small town, and all the locals soon got to know about her and her son and were friendly and supportive.

The summer season ended and the tourists went home. Finally, the big day came. Richard came out of traction and on to crutches. Luckily, a chance meeting with a friend in a pub in Sheffield had revealed that he had a second-hand ambulance. We took this across on the Portsmouth ferry, navigating foggy country roads at night.

After a couple more days, while Richard got used to using his legs again and we had a final holiday, we drove back.

The whole episode had cost us about pounds 3,000. But had we had to repatriate Richard from Florida or the Far East, the price would have been much higher.

So the lesson is simple. Take out private insurance, and above all make sure it covers the full cost of travel and maintenance for relatives to visit the sickbed and for repatriation.

And that bill from the Tresor Public? That was only pounds 285 - a bargain for two months in a hospital room, and no more than any French patient would have paid. It was the other costs that hurt. The bill is a souvenir of the family holiday we spent in a French hospital.