State officials warn beachgoers to watch for four species this summer: lion’s mane, Atlantic sea nettle, moon jellyfish and sea walnut. If stung, they advise rinsing the affected area with vinegar, then treating it with hot water or a warm towel.

Getting stung by a sea walnut would be quite the achievement considering they're ctenophores and dont even have the stings. Which the place they link to even says, rather than warning of them.