A stretch of the Manzanilla Beach on Trinidad’s  Atlantic Coast has been swarmed by thousands of  Portuguese Man of War jellyfish.

Sea bathers and beachcombers have been warned to stay away from the shoreline for fear of injury that includes excruciating pain.

 “For humans, a man-of-war sting is excruciatingly painful but rarely deadly. But beware—even dead man-of-wars washed up on shore can deliver a sting,” National Geographic reports in its description of the pretty purple and blue species than washed ashore in Trinidad earlier this week.

Usually spotted in Trinidad during Easter time,  it has been observed that climate changes dictate that they can wash ashore anytime during the year.

  “Man-of-wars are found, sometimes in groups of 1,000 or more, floating in warm waters throughout the world’s oceans. They have no independent means of propulsion and either drift on the currents or catch the wind with their pneumatophores. “To avoid threats on the surface, they can deflate their airbags and briefly submerge,” National Geographic explains.

Experiments have shown that the best way to treat a sting from a man o’ war is to rinse the wound with vinegar to remove any residual stingers or bits of tentacle left on the skin, and then immerse the wound in hot water—ideally at a temperature of 113 degrees F (45 degrees C)—for 45 minutes. Or use a hot pack instead.