Beachgoers looking to beat the heat on Australia's east coast need to be on the lookout for a familiar and unwelcome visitor, with vast numbers of bluebottles being pushed onshore by strong winds.

Director of the Australian Marine Stinger Advisory Service, Lisa-ann Gershwin, said the striking blue jellyfish lived in armadas in the middle of the ocean and had a keel-like crest and trailing tentacles.

"Bluebottles have definitely been fairly rambunctious lately, pretty much throughout south-east Queensland, they've been coming in in large numbers in a lot of places," Dr Gershwin said.

"They are also appearing at beaches in New South Wales, Victoria and Tassie — we've been getting them in a lot of places."

Bluebottles, pictured here on a Sydney beach in recent years, can still sting after being washed ashore. ( Supplied: Kim Colville )

Dr Gershwin said a bluebottle's crest acted like a sail and they were pushed along by strong winds.

"They get picked up by the wind and blown as long as the wind keeps going or until they hit land and strand on the beaches, so that's when we see them obviously," Dr Gershwin said.

"Some of the bluebottle sails are right-handed and some are left-handed, across the body, so when the wind comes up it only grabs the ones with the sail going the right way for that particular breeze.

"It's nature's way of making sure the population never becomes extinct."

Thousands stung

According to Surf Life Saving Queensland, during the past week, since December 28, 13,243 bluebottle stings have been treated by lifesavers and lifeguards across Queensland, many at popular beaches on the Gold Coast and the Sunshine Coast.

Since December 1, more than 18,000 stings have been recorded in Queensland compared to just more than 6,000 for the same period last year.

A bluebottle warning sign has been erected on Port Macquarie's popular Town Beach. ( ABC Mid North Coast: Emma Siossian )

The organisation said the spike in stings was a timely reminder for beachgoers to exercise caution and swim at patrolled locations where surf lifesavers and lifeguards could monitor the water and respond to any incidents.

Further south, a senior lifeguard at Port Macquarie on the NSW mid-north coast, Kye Polverino, said they had been seeing around four to five people stung by bluebottles each day over the past week.

"We have had bluebottles around, although we haven't had those big swarms yet, so hopefully it stays that way," he said.

Hot water or ice the best treatment

Over the years remedies for treating bluebottle stings have included ice, vinegar and urine.

Dr Gershwin said the best treatment was quite simple.

"The hands down best remedy for a bluebottle string is the one endorsed by the Australian Resuscitation Council," she said.

"They recommend you rinse well with seawater to rinse away any of the stinging cells still on the skin that haven't injected venom yet, and then use hot water or ice for the pain.

"Fresh water will actually force the stinging cells to inject more venom, so you really want to wash them away with the seawater before you apply the ice or hot water."

Surf Life Saving Queensland recommends people ideally place the affected area in warm water for around 20 minutes, or if there is no warm water available, apply an ice pack.

'Fascinating' creatures

A beached bluebottle seen in late afternoon light at Carpenter Rocks in SA. Strong winds can push them ashore in vast numbers. ( Supplied: ABC Open contributor Laurie Dacy )

Dr Gershwin, who is also the co-creator of The Jellyfish App for species identification, said bluebottles were an intriguing species and each one was actually made up of several colony members.

"They're fascinating — the bluebottle that we see isn't actually an individual, it's a colony, like a coral colony; they are comprised of numerous individuals stuck together in the same place," she said.

"The stinging cells are even more amazing … they are all over the tentacles, they are saturated with stinging cells, and each microscopic stinging cell is like a little capsule with a harpoon coiled up inside and bathed in venom and it's got a little hair trigger at one end.

"When it gets triggered by touching our skin or a fish, the stinging harpoon comes flying out of this capsule at 40,000 times the force of gravity, acting as a needle injecting venom … they are just amazing."

Lifeguards urge swimmers to be careful in strong winds

Lifeguards warn beachgoers to swim between the flags. ( ABC Mid North Coast: Emma Siossian )

The strong winds that have been pushing the bluebottles onshore have also been creating unpredictable beach conditions in some areas.

"Obviously it gets choppy, so we get a lot of short interval swell, so wave, after wave, after wave," Mr Polverino said.

"It means more water is getting pushed in and it makes rips a bit stronger.

"It also makes rips are bit harder to spot if you're not used to looking for them.

"So, it is important when you are out there to make sure you are swimming between the flags and also are checking your position because there is a lot of water moving around."