As temperatures reach sweltering levels in the Bay of Plenty, more and more people are heading to the beaches to cool down.

But there is one little critter hiding in the sand waiting to pounce. The dreaded Mount mauler is back and is making some people think twice about going to the beach.

Dion's first new year swim at the Mount on January 1 was met with the unusual sensation of small sharp stings while in the breakers.

Two days later, Dion was itching from head to foot.

"The bite like rash mainly occurs where the tiny Thimble Jellyfish are trapped between skin areas such as armpits or the groin and under swimming garments where they press against the skin.

"The symptoms range from mild to severe depending on the individual allergic reaction.

"Symptoms can persist anywhere from 3 days to 2 months after exposure to the stings."

Dion says they seem to congregate in patches along the coast.

"From my personal experience, if you encounter the stinging sensation while swimming, either move back into shallower water or move along the beach 100M and try again."

Dion's reaction. Supplied photo.

For those new to the Mount and Papamoa, the ‘Mount mauler' is the local name for a kind of beach insect that lives principally above the high-tide mark.

In the past, sunbathers have complained of coming home and finding themselves covered in bites, although most people only get them on their feet from walking across the dry sand.

To avoid being bitten by the Mount mauler, people are advised to stay below the high-tide mark, and spray themselves and their towels with insect repellent.

For more information visit: https://dermnetnz.org/topics/sea-bathers-eruption