You don’t need to tell us twice.

Cork City Council has issued a warning to beachgoers to be extra careful on the sand and in the water after a number of Portuguese Man of War jellyfish (Physalia physalis) were spotted at Barleycove Beach.

“Portuguese Man of War jellyfish (Physalia physalis) have been noted over the last few days at Barleycove Beach,” the County Council said in a statement.

“Following consultation with the HSE a Prior Warning Notice advising the public exercise caution to avoid coming into contact with these jellyfish has been issued today.”

The long tentacles of the Portugese Man of War are capable of delivering a painful sting powerful enough to kill fish and even occasionally humans.

Portuguese Man of War jellyfish (Physalia physalis) have been noted over the last few days at Barleycove Beach following consultation with the HSE a Prior Warning Notice advising the public exercise caution to avoid coming into contact with these jellyfish has been issued today pic.twitter.com/GkLFogxL8J

— Cork County Council (@Corkcoco) September 14, 2020

According to the HSE, a sting from the Portuguese Man O’War “can cause symptoms such as muscle spasms, headaches, diarrhoea, difficulty breathing, heart rhythm problems and other symptoms.”

Usually found in tropical and subtropical waters, the jellyfish are driven by the winds, currents, and tides so stormy conditions can push them towards beaches.

If you do happen to be stung by a Portugese Man of War jellyfish, the medical advice is to use hot water (approximately 45° Celsius) to flush the wound for 20 minutes while you seek medical attention.