Final answer:
To treat Cnidarian stings, remove tentacles, rinse with vinegar, soak in hot water, and seek urgent medical attention for severe reactions.
Step-by-step explanation:
The treatment for stings from Cnidarians such as jellyfish, fire coral, and Portuguese Man o' War involves several steps. First, it is important to carefully remove any tentacles from the skin, preferably using a tool like tweezers, to avoid further envenomation. Next, rinsing the affected area with vinegar to neutralize the toxins is recommended, followed by soaking the area in hot water, if possible, to alleviate pain and inactivate the toxin. It is crucial to avoid rubbing the sting area and using fresh water because these actions can trigger the release of more venom from the nematocysts. For severe reactions or stings from more dangerous species like the box jellyfish, urgent medical attention is necessary as they can be life-threatening.