It’s quite a sight to herald the arrival of a lifesaving doctor: 30 flaming rolls of toilet paper.

In the vast, dusty rangelands of northern Australia, emergency medical help has to travel by airplane. For Geoff Cobden, a pilot for the Royal Flying Doctor Service, that often means a nighttime landing or takeoff from the rough, packed-dirt airstrip of a cattle station. To make the strip visible in the dark, the station can usually set out flares — but what if the flare supply runs out?

“It doesn’t happen often, but when there’s no flares, we set fire to dunny rolls,” said Mr. Cobden, 51, using the bush vernacular for toilet paper.

Melanie Smith, the manager of a roadhouse at the huge Canobie cattle station in Queensland, explained how it’s done: “You soak the toilet rolls in diesel, put them in empty pineapple or coffee tins and line 30 of them up,” she said.

Then you listen for the sound of propellers and watch the sky. When Mr. Cobden’s twin-engine Beechcraft B200C comes into view, she said, it’s time to light the toilet rolls, which will burn for about half an hour.