Despite doing all of the above, some wounds will require surgical cleansing and repair, antibiotics for infection control, as well as antivenins and life support for severe stings. It is not always immediately obvious which stings will need more intensive medical care, so if at all possible, get care for all stings. Their weapons are nematocysts, stinging cells filled with venom and a coiled thread adorned with a barb at its business end. When triggered, the nematocyst fires and harpoons you with enough force to penetrate your skin and inject venom. Hydroids such as fire coral produce an immediate burning sensation followed within 30 minutes by an itchy rash that takes several days to heal.
Jellyfish stings cause burning and leave a trail of bumps and welts.
Serious jelly encounters can result in a severe burning sensastion, muscle spasms, vomiting, shock, even collapse. Remove tentacles with a gloved hand or tweezers to keep from getting stung and then rinse thoroughly with salt water. Fresh water or rubbing will trigger unfired nematocysts. Deactivate remaining nematocysts with a 5 percent vinegar solution until the stinging stops. Use isopropyl alcohol if you don't have vinegar.