Like cast members on a distasteful reality show, Portuguese man-of-war "jellyfish" are descending upon the Jersey Shore in increasing numbers.

Last week, one of these venomous creatures (which are related to jellyfish) washed up in Harvey Cedars, a town on Long Beach Island, New Jersey. This week, four more of the stinging critters came ashore along the same stretch of beach and other specimens were reported elsewhere on the island. [Dangers in the Deep: 10 Scariest Sea Creatures]

But don't panic (yet). There are a number of rules you can follow to avoid getting stung by a man-of-war:

Rule No. 1: Don't touch it

Man-of-war fish have stinging cells that are still active and capable of stinging even after the creature is dead, according to Paul Bologna, associate professor of biology at Montclair State University in New Jersey. But these cells are like a "mouse trap," Bologna told LiveScience. If you don't touch them, they won't hurt you.

Rule No 2: Listen to lifeguards

Of course, if you happen to be swimming in the water near one of these creatures, avoiding a sting might be harder to do. Man-of-war "jellyfish" have tentacles that typically extend about 8 feet (2.4 meters) under the surface of the water, according to Bologna. But their tentacles can grow to be much bigger than that, with some growing to be as long as 165 feet (50 m), according to the National Geographic Society.

For the past few weeks, lifeguards on Long Beach Island have been verbally warning swimmers to stay out of the water whenever one of these venomous critters washes ashore, according to Randy Townsend, lifeguard captain of the Harvey Cedars Beach Patrol. Townsend told LiveScience that lifeguards also post signs and update their social media pages with information about the creatures.

Rule No. 3: Don't pee on it

If you follow these first two rules and still are unlucky enough to get stung by a man-of-war, then you'll want to heed this next guideline. You may have heard that peeing on a jellyfish sting makes the stinging sensation go away, but that's not the case. A 2011 study conducted at the Straub Clinic & Hospital in Honolulu found that urine might actually make jellyfish (or man-of-war) stings worse. Emergency medical experts and lifeguards (including Harvey Cedars' Townsend) agree.

What might help you feel better if you get stung is fresh water, according to Townsend, who said the lifeguards in Harvey Cedars are trained to first remove any tentacles that might have clung to the skin of someone who has been stung by a jellyfish and then to wash the sting with fresh water. Cold or hot compresses help, too, he said.

Bologna also stressed the importance of removing any tentacles that might remain on the skin (remember to use a credit card or other object, not your bare hands). But in addition to rinsing the sting with fresh water, Bologna said that he and his team of researchers keep a little jar of vinegar around when they go on dives where jellyfish may be present. Vinegar, and other acidic compounds, may help ease the pain of a sting, according to the Honolulu study.

Rule No. 4: If you have a bad reaction, seek medical care

Man-of-war stings are almost always more severe than the stings of smaller, less venomous jellyfish, according to Bologna, who said that people's reactions to the stings of these animals depend on their weight (small children are more likely to react badly) and their sensitivity to animal venom in general.

"Anybody who might be allergic to bee stings may have an allergic reaction [to man-of-war stings]," said Bologna.

If you're stung by a man-of-war and you have trouble breathing, that could be a sign of a severe allergic reaction, and you'll want to see a medical professional immediately. Extremely painful stings also require medical attention, as do stings that make you feel dizzy or disoriented, according to Bologna, who said that these symptoms are associated with the neurotoxins in a man-of-war's venom.

Follow Elizabeth Palermo @techEpalermo. Follow LiveScience @livescience, Facebook & Google+. This story was originally written for LiveScience and was republished with permission here. Copyright 2015 LiveScience, a Purch company. All rights reserved.

Related on LiveScience and MNN: