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Jellyfish stings: first aid

Jellyfish stings cause immediate pain, redness, and stinging welts. Correct first aid neutralizes stingers and reduces pain.

Do this now

  1. Rinse the sting area thoroughly with vinegar (acetic acid) for at least 30 seconds to deactivate stinging cells.
  2. Carefully remove any remaining tentacles using tweezers or a gloved hand (do not rub with a towel or bare hand).
  3. Soak the affected area in hot water (as hot as comfortably tolerable, around 40 to 45 degrees Celsius or 104 to 113 degrees Fahrenheit) for 20 to 45 minutes.
  4. Watch for signs of a severe allergic reaction or systemic poisoning.
  5. Seek immediate emergency care for stings to the face, neck, eyes, or genital area.

What to do for most jellyfish stings

  • Vinegar rinse: Household vinegar inactivates the stinging capsules (nematocysts) of most coastal jellyfish.
  • Hot water soak: Immersing the sting site in hot water breaks down venom proteins and eases pain far better than cold ice packs.
  • Tentacle removal: Pluck tentacles off gently with tweezers. If tweezers are unavailable, brush them off with the edge of a credit card.

What not to do for jellyfish stings

  • Do not rinse with fresh tap water or bottled drinking water. Fresh water triggers unexploded stingers to fire more venom into the skin.
  • Do not rub the area with sand, towels, or hands.
  • Do not use human urine, alcohol, or ammonia. Medical studies show these home remedies do not work and can worsen stings.

Dangerous species: Box Jellyfish and Irukandji

In tropical oceans (including parts of the Indo-Pacific and Northern Australia), certain species like the Box Jellyfish or Irukandji carry deadly venom.

Warning signs of severe marine envenomation: - Severe, unbearable pain spreading throughout the body. - Difficulty breathing, chest tightness, or choking. - Nausea, vomiting, sweating, and severe agitation. - Collapse or loss of consciousness.

Call emergency services immediately if box jellyfish or dangerous marine species are suspected.

... note "Beach safety" Always obey lifeguard warnings and warning flags at public beaches. Wearing a full-body lycra suit or wetsuit provides effective protection against jellyfish stings when swimming in high-risk coastal waters.