Stinger experts are warning of a potentially big season for deadly jellyfish with several stings already recorded in north Queensland.
The Queensland Ambulance Service said two people have been hospitalised in the past eight days from jellyfish stings, including one at Clifton Beach near Cairns and another in the Whitsundays.
Surf Lifesaving Queensland northern supervisor Jay March says protective enclosures — each around 200 metres in length — are being installed at more than a dozen beaches across Far North Queensland this week, including the popular tourist spots of Port Douglas and Palm Cove.
He says lifesavers will be conducting drags within stinger enclosures three times a day, on the hunt for the potentially deadly irukandji jellyfish.
"We have had a lot of early rain; it's hot, the water is warm and northerly winds, which is concerning," Mr March said.
"Our drags are turning up indicators for jellyfish, usually plankton that we find in the water generally around the same time."
He says the nets do not protect swimmers against the tiny irukandji jellyfish, which are small enough to slip through the nets.
"We have a pretty good handle on when they (irukandji) are around and we will close beaches if they are present," he said.
"The best thing you can do is cover up as much as possible, wear a stinger suit, a rash vest and remember vinegar is still the best treatment for a sting."
'Feels like a power drill'
According to the federal Department of Health, a sting from a box jellyfish can cause severe pain, and in some cases a person's heart may stop, causing death.
Irukandji symptoms normally occur around 30 minutes after a sting, including severe pain, increased heart rate, vomiting and, in rare cases, damage to the heart.
James Cook University stinger expert and PhD candidate Scott Morrissey said it was difficult to tell what factors influence the presence of more deadly jellyfish some years over others.
But he says it is no secret how excruciating a sting can be.
"It's incredibly painful; some describe it as like someone taking a power drill to your lower back, you can vomit for up to 12 hours and your heart rate increases, which can potentially lead to a heart attack," Mr Morrissey said.
He is working on developing a forensic genetic tool, which can detect the presence of box jellyfish in the water.
"So instead of spending hours and hours dragging nets, we can simply take a water sample and look for their DNA in the water," he said.
