What To Do if You’re Bitten by a Portuguese Man O’War or Stung by a Weever

We (the Portuguese) get a bad rep for naming the Portuguese Man O’War, a jellyfish-looking blueish bubble that stings and hurts like hell. However, we had nothing to do with the discovery. These creatures exist all over the world, especially, Atlantic, and were so named because they (supposedly) resemble a Portuguese caravel at full sail. They are not more common here than in Spain, Florida, or even Hawaii. However, if you’re worried about fish stings in Madeira, here’s some advice.

1. First, you’re not actually “bitten.”

To be fair, a Portuguese Man O’War doesn’t bite — it stings. What people think of as a “bite” is the effect of its long tentacles brushing against the skin. The tentacles contain nematocysts, tiny structures that inject venom on contact. And this nematocysts don’t die, which is why even a dead Man O’War washed ashore, looking like a sad, old freezer bag in the sand, can still sting.

2. Yes, Portuguese Man O’War exist in the Atlantic — including in Madeira and Porto Santo.

Don’t panic. They’re not common every day of the year, but they do appear in both islands, especially when currents and winds push them inland. Spring — usually around Easter time — is one of the periods when sightings increase, because the ocean conditions often bring them closer to shore. In fact, this is why I don’t recommend going to Porto Santo in April. But they can also be found in Madeira, and aren’t easy to spot in the middle of the grey pebble. Most of the time, they look like plastic something left behind.

3. Now, What to do if you’re stung by a Portuguese Man O’War:

Get out of the water immediately and do not rub the area. Rubbing activates more nematocysts, so it will make it worse. If possible, rinse with saltwater (fresh water triggers more stinging), and then apply a cold pack or ice to reduce pain, itching, and swelling. In Madeira, you’re never too far from a bar who’ll gladly give you some ice to help.

Then, carefully remove any remaining tentacle fragments using tweezers or, if you don’t have these on hand (who can blame you!), a card, stick, or gloved hand (not bare fingers). Lifeguards can help removing these fragments and probably have materials on their first-aid kit. Seek medical attention only if the reaction is intense, spreads quickly, or involves breathing difficulty.

4. Man O’War stings are different from weever fish stings.

Now, Portuguese Man O’War is not the same as weevers (“peixe-aranha”). These weevers are sneaky b–stards who bury and camouflage themselves in shallow sand, usually when the tide is turning. However, they don’t want to hurt you. The sting is actually the pain from stepping on the fish’s dorsal spines. Don’t it personally. It was you, not the fish.

The pain is usually sharp, immediate, and gets worse over the first 10–20 minutes, which is different from the intense burning, linear sting of a Man O’War. But the good news is that it also goes away faster. Weavers sometimes appear in Porto Santo, but not in Madeira (which only has pebble beaches).

5. What to do After a Weever Fish Sting:

If you’re stung by a weever, immerse the affected area in water at 40–45ºC, or as hot as you can tolerate without burning, for 30 to 90 minutes. When I first heard this I thought it was myth, but it turns out that the weever venom is heat-labile, meaning heat breaks down the proteins in it. The lifeguards in Porto Santo are ready to help if needed.

6. How to prevent stings in the first place.

The best way to prevent stings is to wear water shoes, which are the useful for pebble beaches anyway. The second thing you can do is ask lifeguards if they’ve seen Portuguese Man o’War or if people have recently been stung by weever fish. From my experience, they’ll reply honestly and will give you good advice. Finally, do not touch any jellyfish-like substances, even if they’re ashore and look dead!