Overview of major box jellyfish stings

Major box jellyfish (Chironex fleckeri) are the most dangerous jellyfish in Australia. They occur seasonally in the far north of Australia. The majority of stings are minor, but rarely severe envenoming can occur. In an adult, severe envenoming occurs with several metres of tentacle-to-skin contact. In a child, severe envenoming has occurred with just over 1 metre of tentacle-to-skin contact. Severe envenoming results in life-threatening systemic effects, characterised by cardiovascular collapse and death within 20 to 30 minutes.