John Coull Hut nearly burned down on April 1, an article in the Federated Mountain Clubs magazine says.
The story is a reminder to people with open fires to dispose of their ashes carefully.
The magazine records that a kayaker arrived that day to find the fire alarm going off and the hut on the middle reaches of the Whanganui River full of smoke. Previous occupants had emptied hot ashes from a fire into a bucket, then put a plastic hearth brush and shovel on top.
The brush and shovel caught fire.
The paddler extinguished the fire and opened the hut windows to let the acrid smoke dissipate. He recorded the narrow escape in the hut logbook.
None of Whanganui's recent house fires was caused by the disposal of hot ashes - but others in the region have been.
FireBuddy Paul Tranter, who sends out monthly fire-related letters to newspapers, recalled another incident. In that one a homeowner discarded the previous night's ashes over the fence onto a neighbouring section.
The ashes were still smouldering and the ensuing fire took hold fast. The final bill for the homeowner was more than $1 million.
"Embers can smoulder for days, so make sure they're left in a metal container in the short term," Mr Tranter said.
When they are finally disposed of embers must be well away from anything likely to catch fire.