Research shows that 75% of potentially fatal stings from jellyfish can be prevented by wearing a stinger suit which is not recognised as skin and thus keep the jellyfish from firing off their venom.
When you are swimming or diving in a new area always ask the locals or lifeguards. They should be able to tell you if there are any jellyfish around or a sudden influx of these creatures locally. They tend to be seasonal and come in swarms into swimming areas, or they arrive after a storm or strong onshore wind.
The way jellyfish feed is by enveloping their prey in their tentacles and paralysing them with "nematocysts", tiny bags full of venom on the tentacles. On contact with a fish or human skin they fire off, releasing the poison into whatever they are in contact with. If this happens to be you or a friend then you need to act quickly.
Get out of the water as soon as you can and have someone help get any tentacles off your skin. They must first of all stop any remaining nematocysts from firing off and the best thing for this is ordinary household vinegar. Pour this over the area affected and on any remaining tentacles. If there is no vinegar handy then there are other fluids you can use, the best of which is urine, which may seem bizarre but has good medical grounding due to its relative warmth and acidity.
Having been doused in whatever liquid try to take off any remaining tentacles with gloved hands so you don't get stings on your fingers. Depending on what sort of jellyfish it was, appropriate action needs to be taken.
If you were hit in Eastern Australia by the deadly Box Jellyfish, you need to get some anti venom as soon as possible and go under medical supervision for a while. Fortunately most stings are not deadly, just really painful.
Take a simple analgesic such as Ibuprofen and apply some calamine lotion on the affected area twice a day. Finally, if you're diving remember to always look up when surfacing after a dive, as this is where most problems happen. Going up head first into a Portuguese Man-of-War is not the best way to enjoy the sea.
Australia's jellyfish swarm out during the summer months from October to May. The 2001-2002 season has produced the highest number of Irukandji syndromes on record. In total 116 patients presented to the Cairns Base Hospital with Irukandji syndrome; this does not include those that presented to other hospitals or local doctors.
This thin lycra suit is enough to prevent stinging from most breeds of jellyfish. Stinger suits provide protection against Irukandji stings provided that undue pressure is not applied. For example sitting on a jellyfish while wearing a suit could lead to a sting.
Bathers wearing stinger suits are still vulnerable to unprotected areas such as feet, hands, neck and face. So make sure you protect yourself by wearing these snug fitting clothes whenever you go for a swim.
Jellyfish in Thailand come from around mid May to end of October. Make sure you wear appropriate clothing. Kite pants and a rashy or a stinger suit should be enough to enjoy your swim.
From experience the jellyfish to avoid are:
They will leave a burn like mark on the skin, some hurt more than others. If stung, do not rub with hand, this will spread any tentacle around. Pour soda water on area, to wash any jelly bits away. Then get a plant called "Morning Glory" and mix with vinegar. Hold this over the area for around half an hour. Any Thai will know what to do if you say "Mangopune", Thai for jellyfish.
Two foreign tourists were fatally stung while swimming in waters off Koh Pha Ngan.
An Australian man has died from multiple stings by a toxic jellyfish. He died before arriving at a beach-side clinic after receiving massive stings to his legs while swimming off the island's Hat Rin beach. Officials said he suffered terrible pain from the stings which left large welt marks on his legs.
"The long tentacles wrapped around his legs three or four times each. It would have been an excruciating death," an official said.
A day later, a Moroccan woman died from similar stings to her legs after being taken by speedboat to Ban Don Inter Hospital on the nearby island of Koh Samui.
The deaths on the island, which is known for hosting all-night rave parties, have prompted local authorities to warn tourists against swimming in the sea during the monsoon season, when the deadly jellyfish are frequently washed toward the beach by rough seas.
Thai police stationed on the island have since been handing out leaflets warning visitors against swimming,
especially in the latter part of the day and early evening.
But officials said many of the travellers were disregarding the warnings.
"There is a general culture on the island that all is OK," one official said.
Photos were sent in by our enthusiastic readers.