Woman diving into a mountain lake Photo Credit: stockstudioX (iStock).

File photo. Photo Credit: stockstudioX (iStock).

After a long hike in the mountains on a hot day, few things can seem more rewarding than plunging into a pristine alpine lake. Believe it or not, plunging into that alpine lake might be the riskiest thing you do all day and it could even result in your death.

While people tend to view flowing waters as more of a drowning risk, standing water can be just as deadly in Colorado due to something called cold water shock.

This type of shock occurs when the body is immersed in – you guessed it – cold water. It can trigger sudden hyperventilation, heart and blood pressure issues, and even cognitive impairment. While this is happening, your body can also suffer from physical incapacitation, as arms and legs may lose their mobility, thus becoming unable to keep the body above water. All of this can take place in the first three minutes of being in cold water.

Another big concern that comes with entering cold water is hypothermia. Cold water immersion can cause the body's core temperature to plummet and once it drops below 95 degrees, hypothermia sets in, as well as further physical and cognitive impairment.

A key misconception when it comes to the dangers of cold water is that the water must be very cold for negative effects to occur. That's not the case. According to the Weather Channel, cold water shock can be just as severe in water temperatures ranging from 50 to 60 degrees as it is in water that's 35 degrees. Some symptoms can even be triggered in water as warm as 77 degrees.

To put that in perspective, the June 27 water temperature on Lake Pueblo, located at 4,900 feet of elevation, was estimated at 66 degrees. On the same date, Dillon Reservoir, at 9,017 feet of elevation, was estimated at around 57 degrees. It's easy to imagine how cold a snowmelt-filled high elevation alpine lake may be, even in warmer summer temperatures – very capable of resulting in cold water shock and surely below that 77 degree threshold.

Another key misconception is that good swimmers and athletic people are less susceptible to cold water shock. This is also not the case, as athletic people tend to have less body fat, something that can act as insulation. It is possible for people to reduce their reaction to cold water, though this is done by conditioning the body over long periods of time.

Aside from staying out of cold water, wearing a life jacket is the best way to prevent cold water shock from resulting in death. That being said, while a life jacket may prevent drowning, it doesn't prevent heart concerns that come with a rapid uptick in heart rate and blood pressure or hypothermia.

In other words, think twice before diving in. Putting yourself at risk of cold water shock can also put would-be rescuers at risk, as they may enter the water to save you and suffer the consequences. While heroic, this act can turn one drowning death into two.

RELATED: This article discusses what should be done when someone is drowning in a remote area. One key recommendation is that those untrained in technical water rescue avoid entering the water. The mantra included in the article is "Reach, throw, row, don't go" when it comes to first response in most cases.

It's also important to keep cold water shock in mind while participating in activities where you might not be planning to get wet, but will be around water. This is one reason why it's important to always wear a life jacket while paddleboarding, kayaking, and boating.

Colorado provides many great opportunities for water-recreation, but it's important to partake in these activities in a safe manner. Wear a life-jacket and only swim in open water in areas designated for the sport.

Read more about the risks of cold water here.

Director of Content and Operations

Spencer McKee is OutThere Colorado's Director of Content and Operations. In his spare time, Spencer loves to hike, rock climb, and trail run. He's on a mission to summit all 58 of Colorado's fourteeners and has already climbed more than half.


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(3) comments


Usually polar plunges are planned events with supervision by medical personnel.


Such click bait B.S. ever done a real Finnish sauna or a Polar plunge where drop through a hole in the ice into freezing temp water.


So sayeth the Flatlander! Well maybe you're a mountain town newbie who thinks they're local because you have live lived at high elevation for a year or two. Your comment is a false equivalence fallacy, just because "a real Finnish sauna or a Polar plunge" are things that happen, it doesn't mean cold water shock is some fabricated boogeyman. It has and will happen, in fact it did a couple of summers back on one of the lakes, Shadow Mountain (maybe you've heard of it if you're a real outdoors person) near where I live in Fraser, which is near Winter Park, the town with the ski area, not the one in Florida (you seem like the type that would need the clarification.)

If you had the capability of seeing past your cognitive bias, perhaps you would do a simple google search and educate yourself. I don't see that happening, considering that you're already a know-it-all

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