From Hanauma Bay, Hawaii, to Cape Cod, Mass., jellyfish are swarming right now, even forcing some beaches to close to keep swimmers from being stung.
That's because late summer is prime jellyfish season, with warm waters luring them close to shore.
And since you're far more likely to suffer a jellyfish sting than a shark bite, here's what you need to know, step by step, to cool the burn of a sting:
First, don't believe the rumors. Peeing on a stung bit of skin won't do much to relieve suffering, and you'll suffer some odd stares, too, doctors say.
Urine has not been scientifically proven to help in jellyfish stings, said Dr. Paul Auerbach, an emergency physician at Stanford University Hospital and an expert on jellyfish stings.
Instead, vinegar is the best first treatment, he said, when treating stings from North American jellyfish.
First things first, though. If stung by a jellyfish, be sure to get away from the jellies and out of the water to a safe area, he said. If a jelly tentacle is wrapped around an arm or leg, remove it using another object, such as a stick.
The next step is to inactivate the stingers, or nematocysts, that attach to the skin after brushing up against jellyfish tentacles. The best thing to use is acetic acid, or regular household white vinegar, Auerbach said.
In fact, the beaches of Australia are lined with vinegar stands, says Dr. Suzanne Shepherd, a travel medicine specialist and emergency physician at the University of Pennsylvania. Shepherd, who has herself been stung by jellyfish, said she takes vinegar with her when she heads out for a swim in the ocean.
Apply the vinegar by soaking a paper towel or thin cloth in vinegar and gently placing it to over the sting for 30 minutes, said Auerbach. Or pour the vinegar directly over the area. Isopropal alcohol or rubbing alcohol can also inactivate nematocysts, although neither it nor vinegar should be rubbed into the sting, Auerbach said.
Rubbing the sting will cause more nematocysts to fire and that will just mean more pain, he added. Auerbach said he carries a 50-50 mixture of vinegar and rubbing alcohol when he goes to the beach.
While vinegar is the best option, unseasoned meat tenderizer, baking soda, household ammonia, and lemon or lime juice are other things that can also prevent nematocysts from causing pain, he said. Baking soda has been used, particularly on the East Coast where stinging nettle jellies are common.
If using meat tenderizer, it must not be left on the skin for too long since it also can cause a rash.
Shepherd also recommends avoiding fresh water to treat a jellyfish sting because it could just cause the remaining nematocysts to fire.
Once the nematocysts are deactivated, it is safe to remove them from the skin. The best way is to gently apply shaving cream to the area and scrape them off using a safety razor, said Shepherd. If no shaving supplies are available, use sand and a shell to scrape away the nematocysts.
With the nematocysts off, consider using hydrocortisone cream to decrease skin irritation. If it's not strong enough, see your physician for a prescription steroid cream.
The rash from the sting can last anywhere from 24 to 48 hours, although this is highly variable, Auerbach said.