Now that we’ve started getting some downright hot days, people are talking about swimming in the river and other bodies of water in the area. Unfortunately, this can be really dangerous. This is largely because of snowmelt.
For starters, springtime rivers, streams, and creeks tend to run faster and higher as more snowmelt and our spring showers are introduced into them which makes it far easier for someone – especially little someones – to get swept away. Right now, most of Oregon’s rivers are considered to be above their average flow. People often underestimate just how strong currents are. They also overestimate their swimming abilities in such water because they gauge their river swimming abilities on their pool swimming abilities which are not the same. People tire more quickly when they are forced to deal with currents and low temperatures.
The water is also cold. Very cold! This is partly because of that snowmelt again. It’s cold. And there’s a lot of it going into the different river systems. But it’s also because of the weather. There is a LOT of water in our river systems. That takes a while to heat up. One or two warm or even hot days is not enough to bring the temperature of the water up to safe levels. And the deeper the water, the longer it takes to warm up. Even during the summer, warm surface water can hide cold waters underneath.
Why does the temperature matter? Because going into water that is 70° F and below can lead to hypothermia and water 59° F and below can shock your system so severely that it induces a heart attack – even in the young and healthy. Cold water can cause the body to lose heat at a rate 25 times faster than cold air! So even if you are one of those people who feels like they thrive in our long, cold winters, you will still feel the effects of the water. And while we normally think of physical activity as a way to increase our body heat, swimming in water 68° F and below can actually cause you to lose more body heat than if you were to stay still in the water!
The average normal body temperature for humans is 98.6° F. Hypothermia occurs when your body temperature is 95° F or below. It tends to happen gradually so people do not notice they are developing hypothermia. Symptoms of hypothermia include shivering (which stops as the hypothermia becomes more severe), confusion, lack of coordination, faster breathing (which slows s the hypothermia becomes more severe), increased heart rate (which slows s the hypothermia becomes more severe), nausea, and fatigue and drowsiness. Infants might exhibit drowsiness, a weak cry, and bright, red skin. If someone develops hypothermia, get them out of the water immediately and call 9-1-1. Monitor their breathing. Be gentle and move them as little as possible. Do not massage or rub them. Get them out of their wet clothes and surround them with dry blankets so that only their face can be seen. Do not apply direct heat, such as heat lamps, heating pad, or hot water. If they are conscious and alert, they may sip hot non-alcoholic beverages.
Cold water shock is the body’s response to sudden immersion in cold water – such as when someone dives into the river. It can cause death within the first few minutes of entering the water. The sudden cooling of skin temperatures is one of the most shocking stimuli for our bodies. The shock actually causes our bodies to let out one or more huge, involuntary gasps – which if you are still underwater causes you to drown. After the gasp(s), people begin to hyperventilate, which are deep but rapid breaths than can lead to an imbalance of carbon dioxide in the blood. If someone needs to hold their breath for any reason, for instance to deal with a current in their face, they will not be able to do so for very long if at all. At the same time as all of that, the heart begins to need to work harder because of blood vessels constricting throughout the skin. Both a person’s heart rate and blood pressure increase very quickly leading to an increased risk of heart attack and stroke in even the young and healthy. The shock of the cold water can also can changes in mental status with panic, confusion, and drowsiness common, making it difficult to think or move. These symptoms can persist even after the person gets out of the water – on their own or with help. Anyone who experiences cold shock should be gotten out of the water immediately. If they survive those first few minutes in the water, they can still develop swim failure which is where the combination of symptoms plus painful muscles weakened by the cold makes a person, even strong swimmers, unable to swim causing them to drown. Call 9-1-1, even if it is “just” for an evaluation. There can be serious after effects, such as if their blood pressure drops too quickly.
That’s why, for right now, we recommend that no one swims in the river. The water is still far too cold for it to be safe for anyone. We know that the recent days of nice weather have been making the river very tempting for people, but we strongly encourage everyone to find alternative ways to cool down!