You may think that sharks are the most dangerous animal you’ll encounter at the beach. But in places like Hawaii, sharks, which only cause 10 human fatalities a year, are not the marine creature to worry about when swimming. The more serious threat is the box jellyfish—a clear, translucent sea creature that can be lethal when touched. The jellyfish kills over 100 people a year, and Dr. Angel Yanagihara, an assistant researcher for the Pacific Biosciences Research Center at the University of Hawaii at Mānoa, came dangerously close to being one of those statistics.

In 1997, Yanagihara swam through a swarm of box jellyfish during her morning swim. She’d gotten mildly stung by jellyfish before on her swims and didn’t think much of it. Then, an hour later, there was “some kind of needle pricking, but burning feeling,” Yanagihara recalls. “I was wheezing. And I felt like my lungs were filling with liquid. It was just shocking and terrifying. I was convinced that this may be the end of me, that I may be in danger of drowning.”

She made it back to the beach and lost consciousness. She came to in an ambulance. EMTs had wrapped her wound with with meat tenderizer, vinegar, and Saran wrap. “And I just thought, now, this is not proper care,” she says. “What are we doing here?”

[Landlocked for 60 years, these juvenile Atlantic salmon still have the tools to navigate the sea.]

After her recovery, Yanagihara shifted her research focus. “I was very curious to find out the biochemical explanation for something that primitive that can cause so much pain. It had my full attention,” she says. She learned how many deaths box jelly stings cause and just how many ineffective sting treatments there are on the internet.

Dr. Yanagihara learned the painful sting comes from explosive cysts on the surface of the jellyfish called cnidae. The cnidae contain microscopic tubules that, when triggered, cause a barbed tip to shoot out like a bullet, piercing the skin. The tubule follows within microseconds, discharging venom, which starts attacking blood immediately. Using these findings, she developed a line of topical products that isolate the cnidae and cause them to rupture en masse.

But if you don’t have access to the topical products at the beach, Yanagihara recommends rinsing the wound in vinegar and submerging it in water between 108 and 113 degrees Fahrenheit for 45 minutes.

Despite her work, there remains a lot of misinformation online on how to treat a box jelly sting—and it’s costing people their lives. “We need to be evidence-based, not opinion-based,” Dr. Yanagihara says. “Because in the end, to make contributions to human health, we need that deep understanding and deep knowledge.”