Summer holidays in tropical Australia mean reef trips, island hopping and long days on the beach. They also coincide with stinger season, when box jellyfish and Irukandji are most common in northern waters. Knowing where the risk is, how to lower it and what to do if someone is stung can make a real difference.
This guide covers box jellyfish, Irukandji and bluebottles in Australia, first aid for each, and what to know if you are heading to tropical beaches overseas.
Key points
- Stinger season in tropical Australia typically runs from November to May, though it varies with location and weather.
- Box jellyfish and Irukandji are found in northern Queensland, the Northern Territory and northern Western Australia.
- For a tropical jellyfish sting, call 000 and pour vinegar on the sting for at least 30 seconds. Start CPR if the person is unresponsive and not breathing normally.
- For bluebottle stings, rinse with sea water, remove tentacles and use hot water (45°C) for 20 minutes. Do not use vinegar.
- Stinger nets help with larger jellyfish, but Irukandji are small enough to pass through, so a full-body stinger suit is recommended.
Heading somewhere tropical these holidays? A TMA travel doctor can help you plan for the trip.
When is stinger season in Australia?
Surf Life Saving Queensland describes the marine stinger season as typically running from November through to May, when the risk from the two most dangerous species is higher. Healthdirect notes the season is usually late spring to early autumn and varies by location and weather, so check local warnings wherever you swim.
Where are box jellyfish and Irukandji found?
According to Surf Life Saving Queensland:
- Box jellyfish (Chironex fleckeri) live in shallow tropical waters north of Agnes Water in Queensland, and in Northern Territory and Western Australian waters south to Exmouth.
- Irukandji are found in tropical waters north of southern K'gari (Fraser Island), in the Northern Territory, and in Western Australia south to Exmouth.
Healthdirect advises treating any unidentified sting in the north, north of Bundaberg in Queensland and Geraldton in Western Australia, as a box jellyfish sting. Popular holiday spots in these zones include Cairns, Port Douglas, the Whitsundays, Townsville, Darwin and Broome.
What are the symptoms of a jellyfish sting?
Box jellyfish
Box jellyfish are the most dangerous jellyfish in Australia. Healthdirect describes severe pain and red, whip-like lines on the skin. In severe cases breathing can stop and the heart can stop, potentially within 20 to 30 minutes.
Irukandji
Irukandji are tiny, transparent box jellyfish, usually only 1 to 2 cm across, so most people never see them. The sting itself can feel minor. Surf Life Saving Queensland explains that 5 to 40 minutes later, a person can develop severe generalised muscle pain, headache, vomiting and sweating. Healthdirect also lists severe back, abdominal and chest pain, a fast heart rate, high blood pressure, anxiety and agitation. This is known as Irukandji syndrome, and severe cases can affect the heart.
Bluebottles
Bluebottles are common along the east coast, especially in Queensland and New South Wales. A sting causes intense pain that can last an hour or more and a red line on the skin that may last a day or more. Bluebottle stings are painful but usually do not need medical treatment.
Jellyfish sting first aid
Tropical stings (box jellyfish and Irukandji)
- Get the person out of the water if you can do so without putting yourself at risk, and call triple zero (000).
- Pour vinegar liberally over the sting area for at least 30 seconds. Vinegar deactivates stinging cells that have not yet fired.
- Pick off any remaining tentacles. If there is no vinegar, wash them off with sea water, not fresh water.
- If the person is unresponsive and not breathing normally, start CPR straight away.
- Keep the person still and watch them closely. Surf Life Saving Queensland advises monitoring people with possible Irukandji stings for 45 minutes, as symptoms can be delayed.
- Ice packs can help with pain while you wait for help.
Bluebottle and other non-tropical stings
- Rinse the area with sea water and remove any tentacles.
- Place the stung area in hot water at around 45°C (as hot as can be comfortably tolerated without burning) for 20 minutes. Healthdirect notes hot water works better than ice packs.
- Do not use vinegar on bluebottle stings, as it may increase pain.
- Call 000 if pain persists or is widespread, or if the person has difficulty breathing.
| Where you are | Use vinegar? | Heat or ice | Call 000? |
|---|---|---|---|
| Tropical north (box jellyfish or Irukandji possible) | Yes, at least 30 seconds | Ice packs for pain | Yes, always |
| Bluebottle, anywhere | No | Hot water, 45°C for 20 minutes | If pain persists, spreads or breathing is affected |
How to avoid jellyfish stings
- Swim at patrolled beaches, between the flags, where lifesavers can give first aid.
- Follow warning signs and stay out of the water when jellyfish warnings are in place.
- Wear a full-body stinger suit or wetsuit in tropical waters during stinger season, including when snorkelling and diving on the reef.
- Do not rely on stinger nets alone. Research reported by SBS News found Irukandji are small enough to pass through the nets, and most Irukandji stings in the study occurred inside netted areas.
- Do not touch jellyfish in the water or washed up on the beach.
- Check that your tour operator or accommodation carries vinegar and first aid supplies.
Box jellyfish overseas
Box jellyfish are not only an Australian issue. They are also found in parts of Southeast Asia, and deaths of tourists from box jellyfish stings have been reported in Thailand, including on Koh Samui, where Thai authorities have asked beach businesses to keep vinegar ready for first aid.
When travelling to tropical beaches overseas, ask locally about jellyfish, swim where there is lifeguard cover, and pack a small bottle of vinegar in your beach bag. Remember that medical care and evacuation can be much harder to reach in some destinations, so travel insurance that covers emergency evacuation is worth checking before you go. Our guides to vaccinations for Thailand and vaccinations for Bali cover the other health risks to plan for.
Frequently asked questions
When is stinger season in Queensland?
Typically from November to May, though jellyfish can be present outside these months. Always check local warnings.
Do you put vinegar on a jellyfish sting?
Yes for tropical stings from box jellyfish or Irukandji, and for any unidentified sting in northern Australia. No for bluebottle stings, where vinegar can increase pain and hot water is recommended instead.
How long after an Irukandji sting do symptoms start?
Usually between 5 and 40 minutes after the sting. This is why people who may have been stung should be monitored, even if the sting felt minor.
Do stinger nets protect against Irukandji?
Not fully. Nets help keep out larger box jellyfish, but Irukandji are small enough to pass through. A full-body stinger suit gives more protection.
Can you swim in Cairns or Port Douglas in summer?
Many people swim in these areas during stinger season by choosing patrolled beaches, swimming inside nets, wearing stinger suits and following lifesaver advice. Check local conditions and warnings each day.
Plan your summer travel health with TMA
Whether you are heading to the Top End or a tropical island overseas, a pre-travel appointment with a Travel Medicine Alliance (TMA) doctor can help you plan your vaccines, travel medical kit and what to do if you get sick or injured while away. TMA clinics have substantial experience in travel medicine and are located across Australia.
Find a TMA travel doctor near you.
This article provides general information only and is not a substitute for individual medical advice or first aid training. In an emergency, call triple zero (000).