It’s best to treat any painful jellyfish sting rapidly and seriously, even if you don’t know what kind stung you. While some kill within minutes, other box jellyfish stings can lead to death in four to 18 hours.
If you witness a box jellyfish sting, immediately do the following:
- Help the person exit the water and try to keep them calm.
- Call 911 or other emergency medical personnel.
- Put hot water, vinegar, or baking soda on the sting, if available. If not, put salt water on it. That will help stop the release of venom. Avoid fresh water.
- Remove any tentacles that you see in the skin. Do this with a knife, tweezers, or some other sharp object. Only use your hands if covered with rubber gloves—never use your bare hands.
- If the person is unconscious, start CPR if you know how to do it.
Medical professionals can perform resuscitation, which may keep the person alive until the reaction to the venom weakens.
Experts in Australia developed an antidote to the most deadly form of box jellyfish sting, which works in about 15 minutes, but getting it to victims in time is a challenge.