How to prevent and treat venomous jellyfish stings in Thailand

Venomous jellyfish are no joke and are found in Thailand’s waters all year round. Don’t worry, you don’t have to cancel your beach holiday, just learn the necessary tips to prevent and treat jellyfish stings and you’ll be all set.

If a jellyfish warning sign is up at the beach, stay out of the water. Some venomous jellyfish such as fire jellyfish – one of the smallest yet most venomous jellies in the world – like to swim in their thousands. Surviving a fire jellyfish swarm would be very difficult.

Don’t ignore a red flag. Whether the red flag is a warning against choppy conditions, a shark, or a smack of jellyfish, it is not safe to swim. Tourists ignoring red flags at the beach in Thailand or anywhere has tragic consequences.

Do not underestimate the danger posed by toxic jellyfish. Jellyfish venom attacks the cardiovascular system and can cause the human heart to stop beating in just two to five minutes. Untreated jellyfish stings can be fatal.

Preventing jellyfish stings

  • Keep a look out for jellyfish warning signs.
  • Swim inside the net if the beach has a designated swimming area.
  • Keep your eyes peeled for jellyfish while swimming.
  • Beware of ‘beached’ jellyfish – they can sting even if they are dead.
  • Do not swim in the sea after rain, at night, or outside the jellyfish buoys.
  • Wear clothes that cover your body while swimming.

Treating jellyfish stings

  • Get the injured out of the sea to a safe place and have someone call an ambulance (1669).
  • Keep the injured calm and still. Moving will cause the venom to move around the body.
  • If the injured is unconscious, perform CPR before pouring vinegar on the wound.
  • Pour vinegar over the affected area continuously for 30 seconds. Vinegar should be available at all beachside resorts. If you’re going to a remote beach, take your own bottle of vinegar.
  • Do not pour still water or rub sand into the wound.
  • Observe the injured for 45 minutes. Watch for severe pain, restlessness and confusion, sweating, chills, vomiting, chest pain, heart palpitations, chest tightness, difficulty breathing or skin discolouration – seek urgent medical attention.

Box jellyfish can be found in the seas of southern Thailand.

Single-tentacle box jellyfish stings can cause people to experience muscle ache, nausea and even paranoia. Stings from box jellyfish with multiple tentacles are more deadly, causing a rash or burn. A bad sting can cause lightheadedness, the heart to stop, respiratory failure and eventually death in 2 – 10 minutes.

Since 2002, ten people in Thailand have died from box jellyfish stings – nine in the waters of Koh Samui, and Koh Pha Ngan.

Last August, a nine year old Israeli boy died from a box jellyfish sting on Koh Pha Ngan.

In March, hotel staff all over Koh Samui came together to learn how to prevent and treat box jellyfish stings in particular.

Thailand News


Leah is a translator and news writer for the Thaiger. Leah studied East Asian Religions and Thai Studies at the University of Leeds and Chiang Mai University. Leah covers crime, politics, environment, human rights, entertainment, travel and culture in Thailand and southeast Asia.

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