Lenny's Story has made me want to share our experience over the last 2 weeks, which maybe helpful to others
My brother was very sick so we did a very quick search of the forums etc and decided that BIMC was the best place to take him.
He was diagnosed as having dengue fever and had a few trips to BIMC. On the 2nd or 3rd visit they said he needed to be hospitalised.
At this stage he asked me to act on his behalf and contact his insurance company. He had booked his flights with his bank west gold visa card so I rang them. They were very good but said that even though he was diagnosed by BIMC they needed him to be diganosed by their preferred medical centre at be covered. The medical centre was SOS. We took him to SOS and they did all the tests again, he was kept there for 48 hours whilst they decided if they would evacuate him to Singapore or Perth - luckily he responded well to the drip they had him on so there was no need for evacutaion.
So in addition to Lenny's advice about carrying your insurance details with you I think (In case of Illness) it's a good idea to phone your insurance provider 1st to find out where you need to go so you will be covered. I know that it was not fun for my brother to go through all the blood tests twice.
To cover him they also needed a copy of his flight itinerary and a copy of his credit card statement showing the original purchase of the flight. Luckily he still had these on his email on his laptop so I could access them and forward them to the insurance company. The insurance company then approved it and paid SOS direct (US$900 per day plus doctor's fees, medication, tests etc...)
NB: We are covered by NAB gold card and their preferred medical centre is BIMC (my son also got sick but nothing serious) so each underwriter is different