Jellyfish sting in Puerto Rico: what to do, including man o' war stings

These are the steps from MedlinePlus, published by the U.S. National Library of Medicine:

MedlinePlus says to protect the affected area and not rub sand on it, apply pressure or scrape the sting site. Don't use remedies that aren't in these instructions. If you are unsure, call Poison Help at 1-800-222-1222, which also serves Puerto Rico.

The Portuguese man o' war looks like a jellyfish, but according to NOAA it is a siphonophore, a close relative. You can recognize its balloon-like float, which may be blue, violet or pink, and its long tentacles, which average about 30 feet.

It lives mostly in tropical and subtropical seas. Its sting is rarely deadly, but it is very painful and causes welts. It can still sting weeks after washing ashore, so don't touch any you see on the sand, and teach children not to touch them.

MedlinePlus gives the same first aid for all types of jellyfish.

Most stings cause pain, burning and welts on the skin. According to MedlinePlus, a Portuguese man-of-war sting can also cause belly pain, changes in pulse, chest pain, chills, headache, muscle pain and spasms, numbness, sweating and, in severe cases, collapse.

MedlinePlus says to get medical attention right away if pain increases or there are any signs of breathing difficulty or chest pain. In that case, call 911. See also when to go to the ER.

For stings that aren't emergencies, we offer virtual urgent care. In a doctor visit, Dr. Diana Nieves Castro, MD, a Puerto Rico-licensed general practice physician with several years of emergency-department experience, looks at the sting, evaluates pain, itching or swelling, and checks for signs of infection in the days after. If appropriate, the doctor prescribes and we send your prescription to your pharmacy.

Doctor online 24/7: video doctor visits 24/7 — book online and choose your time right away. We send you a secure video link; it works on your phone, tablet or computer. You must be in Puerto Rico during the visit, and visitors are welcome. More on virtual urgent care.

If you have any sign of a serious reaction, don't wait for a video visit: call 911 or go to the ER. See ER vs urgent care in San Juan.

Children get the same first aid. Test the hot water with your own hand before soaking your child's skin, so you don't scald them. If your child has any of the serious-reaction signs on this page, call 911. We see children of all ages; if the patient is under 21, a parent with patria potestad or a legal guardian stays on the video for the whole visit and shows photo ID.

Check the National Weather Service San Juan beach forecast, which reports rip current risk and the UV index, and follow the flags and lifeguards. There are area guides for beaches such as Isla Verde and Condado. On vacation? See also sick on vacation in Puerto Rico.

If you get an itchy, stinging rash where your swimsuit touches your skin after swimming, it may be seabather’s eruption, an allergic reaction to the larvae of jellyfish or sea anemones that, according to the Merck Manual, affects swimmers in the Caribbean. And if the shore has piles of sargassum, read sargassum health effects. Cut yourself on a rock or a shell? See when a cut needs stitches.