Warm air, cold water: know the risks

In the first five months of this year, 57 people drowned in Portugal, according to provisional data released by the Drowning Observatory of the Portuguese Federation of Lifeguards (FEPONS). This is similar to the same period in 2024 (58 deaths), which constituted the worst period since the beginning of the historical series of the Drowning Observatory, in 2017.

Most drownings are caused by strong sea currents, or by people becoming out of their depth in the ocean, rivers and reservoirs. It is important, therefore, to keep an eye on children in particular, and put safety first before plunging into the sea.

Sea temperatures

At present, sea surface temperatures range from around 17ºC to 19ºC on the west coast and from 19ºC to 22ºC on the south coast. This is not bad compared with average sea temperatures. However, the water can be colder than these temperatures suggest, and with air temperatures at present over 35ºC (and in the sun even hotter), the difference between air and water temperature can be considerable.

Anywhere the water is colder than body temperature, swimmers can be affected by hypothermia at any time of year; it’s just a matter of how long it will take to develop. Mild hypothermia occurs when the body’s core temperature drops to between 35ºC and 32ºC. Effects of mild hypothermia: It suppresses the function of the central nervous system, impairs decision-making, reduces sensation, slows movement and causes shivering.

The only way to recognise your own limits is to know them, through experience.

Warm air doesn’t always mean warm water in lakes, streams or oceans. Water at 17ºC temperature may not sound very cold, but it can be deadly. Plunging into cold water of any temperature becomes dangerous if you aren’t prepared for what the sudden exposure can do to your body and brain.

Hot air temperatures can create a false sense of security for boaters and beachgoers. If you are planning to be on or near the water, make sure you know the conditions and how to protect yourself before you arrive.

Rip currents

A rip current is a narrow, fast-moving channel of water that starts near the beach and extends offshore through the line of breaking waves.

Spotting a rip current can be difficult and really needs some practice. Rip currents are easier to spot from an elevated position, such as a dune or beach access point. Look for places where the waves are not breaking – flat spots in the line of breaking waves. Also look for maybe foam or sediment in the water being transported away from the shore out to sea, as this can indicate a rip current.

Rip currents can occur anywhere, including large sandy beaches, where there are hard structures, like jetties, or piers, or even rocks jutting out into the ocean.

If you do get caught in a rip current, the best thing you can do is stay calm. It’s not going to pull you underwater, it’s just going to pull you away from shore. Call and wave for help. You want to float, and you don’t want to swim back to shore against the rip current because it will just tire you out. You should swim out of the rip, parallel to shore, along the beach and then follow breaking waves back to shore at an angle.

Weever fish or spider fish (peixe-aranha)

Imagine walking along the white sands of a beach. You feel the warmth of the sun, the gentle sea breeze and the fine grains of sand between your toes. Life is good. Suddenly, you think you stepped on something … maybe it was a rock?

But it could be a spider fish.

Stings are most common during the summer months, specifically from June through September. There is initially a mild pain, but it evolves almost immediately to an intense pain, difficult to bear, with changes in the surrounding skin, which becomes red and swollen.

If you can identify the thorns stuck on the skin, try to remove them as soon as possible, with a tweezer or gloves. Don’t touch them with your fingers.

Place the foot or the stung area in some heat source, such as hot sand, or in water as warm as possible, for at least 30 minutes, so the poison will decompose with the heat. Be careful not to burn yourself.

If you are stung on the face, have intense and permanent swelling and pain, persistent fever, nausea, vomiting, dizziness or headaches, excessive sweating or are unable to remove the spikes, you should seek an emergency service.

Never put ice in the sting area, do not touch the thorns with your hands, nor cover the wound of the sting.

You can prevent the spider fish bite by wearing plastic soled shoes when walking in the water.

Spider fish stung pain can last between two hours and 24 hours, and most people stung by spider fish do not need to be seen by a physician.

Emergency medical services should be contacted immediately by calling 112 if a person stung by a spider fish develops shortness of breath, loses consciousness, has convulsions, develops an intense skin rash (red spots on the skin), experiences edema (swelling) accompanied by changes to their voice, or suffers chest pain.

We wish you an enjoyable and safe visit to the many lovely beaches Portugal has to offer.

Previous article by David Thomas: Wildfires – from storms to heatwaves