Broome surfer Josh Cocking was pulling on his rash vest and about to hit the water when he felt a nasty sting.
Trying to ignore the pain, he headed out into the waves, but within half an hour his whole arm had turned red.
It turns out Josh had been stung by a box jellyfish — the same jellyfish that had first stung him five weeks ago, then died.
"The poison was still in the rash vest and it started zapping me up and down the arm as soon as I put it on and went out in the water again," Mr Cocking said.
"That rash vest had been just been sitting outside for five weeks not in water and the sting was still pretty potent."
Its tentacles had remained dormant but painfully poisonous within Mr Cocking's rash vest, teaching the surfer the hard way that water-goers can be stung by jellyfish long after the creatures have died.
Long-lasting stingers
Professor Jamie Seymour is a researcher at James Cook University's Institute of Tropical Health and Medicine.
He said there had been no definitive research done to determine exactly how long a jellyfish tentacle kept its sting after it had died, but estimated it could be thousands of years.
Dr Seymour said he has successfully stored freeze-dried box jellyfish venom for 25 years and it was still viable today.
Dehydration preservation
Dr Seymour said a neurological process took place that told jellyfish when to sting, when they were alive.
"When you dry them [stinging organelles] out, the undischarged ones, the ones that haven't fired off … they sit there as a dehydrated cell organelle," he said.
"They suck up the water and then, when they come in contact with your body, they fire off and venom gets deposited."
At the same time, however, he said researchers did not believe the sting would be fatal, "because we don't think the discharge is as effective as it would be if it was on a live jellyfish".
