UPDATE: About 30 minutes after exiting the water a 12-year-old boy has exhibited symptoms similar to that of an irukandji sting on the upper left thigh, a QAS spokesperson said.
He was taken in a stable condition to Hamilton Island Medical Centre.
It was unable to be confirmed if the sting was a result of an irukandji.
Mackay and Sarina beaches are currently on high-risk alert for stingers as humidity, northerly winds and intermittent rain continues, Queensland Surf Lifesaving lifeguard supervisor Hannah Ridland said.
Drags of the beach have been increased to hourly a box jellyfish was found at Eimeo Beach.
EARLIER: Queensland Ambulance Service said they're assessing a boy who may have been stung by a jellyfish at Hamilton Island.
The boy was stung on the upper thigh and it's suspected it was from an irukandji.
They posted on social media they were at the scene about 3.30pm.
On Saturday in Mackay a box jellyfish was found at Eimeo Beach.
It was the first jellyfish caught for the season.
The juvenile jellyfish measured 6cm across the bell.
Queensland Surf Lifesaving lifeguard supervisor Hannah Ridland said at the time, while it was a juvenile "it would still give a good sting and could be life threatening to a small child".
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