Connect with us


River safety: cold water immersion



By Josh Olsen Contributor
It was a chilly, 65-degree spring day, and I was
guiding a group of kayakers on the river. A client
in his early 30s took a wave on the right side of
his boat, over corrected and ended up swimming.
He gasped for air and clawed at the neck of his
dry top.
I pointed to his kayak and yelled, “swim to your boat!”
He stared at me and bobbed, but because he was
stunned by the frigid immersion, he was unable
to rescue himself. I paddled to him, he grabbed
the handle on the stern of my boat, and dragged
him to shore.
There, he continued gasping and wheezing. I rifled
through a list of possible injuries or illnesses: immersion
syndrome? Water aspiration? Laryngospasm?
I tried to calm his breathing by coaching. Between
stunted exhalations he blurted out, “Asthma.”
After using his inhaler, his breathing slowed. However,
I couldn’t rule out the possibility he may have
inhaled water into his lungs. We continued the float,
and afterward, I recommended he visit the hospital
for a full evaluation. It would have been difficult to
fully attribute the asthma attack to the submersion
event, because fear or anxiety may have been contributing

Cold water can pull body heat away through conduction 25
times faster than cold air. Anyone who has experienced immersion
in a Montana river or lake during the early boating
and fishing season can relate to the crippling effect of cold
water. Cold water immersion, especially in swift moving
water, can make rescue very difficult, as the effects of cold
water can slow motor skills and cloud decision making.
This year, with record snowfall and heavy rains the cold
“spring” runoff could be around for months. By taking a few
precautions during cold water recreation, you can keep your
enjoyment level up and your hospitalization level down:
• Be prepared and dress to get wet.
• Know the flow. Check water levels at americanwhitewater.
org or
• Scout rapids and have a plan if someone swims, decide
on a safe eddy, or rescue plan.
• Wear a personal flotation device that fits. This may seem
obvious, right? But think about the last time you saw
someone at the put-in with a PFD that was too big or
none at all.
• Take a class in swift water rescue from Whitewater
Rescue Institute ( and a class in
first aid or wilderness medicine.

There are also a range of post
immersion related illness and injuries.
A few major concerns are:
Cold water drowning affects
both the respiratory and cardiac
systems and often causes victims
to gasp, aspirating water. This
can lead to asphyxiation. If
a victim is pulseless and not
breathing, s/he needs CPR and
advanced care.
Complications from a submersion
event or death secondary to
drowning, victims may aspirate
water, filling their lungs and
leading to respiratory distress.
Sometimes this condition is
called “parking lot drowning,”
because the victim is often out
of the water and may not manifest
symptoms until well after
the submersion event. Although
these victims may report they
feel “fine,” they need to be
evaluated by a medical professional.
The wilderness medical
society suggests monitoring a
person involved in a submersion
event for 24 to 48 hours
for signs of a wet persistent
cough or respiratory distress.
Post-immersion victims may
develop hypothermia, which is
abnormally low body temperature.
Mild hypothermic
victims often shiver, act confused
and present the “umbles”—
stumbling, fumbling
and mumbling. They may also
be combative or display poordecision
making skills. A hypothermic
victim should not
remain in cold wet clothing. If
possible, encourage the victim
to exercise and eat simple
sugars to increase warmth.
Severely hypothermic people
will stop shivering and have
grossly impaired motor skills
and decreasing responsiveness.
Eventually they will become
unresponsive. Prevent further
heat loss, handle gently and
remember all hypothermic
victims should seek immediate
medical attention.
It can be challenging to differentiate
between drowning,
immersion injury and hypothermia
without advanced
training, as signs and symptoms
can be complex and
As I experienced, a
cold water accident can trigger
other common illnesses such
as asthma or exacerbate other
pre-existing medical conditions.
So, as you enjoy this
season on Montana’s beautiful
rivers and lakes, remember
prevention through preparation
will be your best defense
to a cold water accident.

Basic rescue:

If you are involved in a rescue, remember
your priorities. First, do not make yourself a

As the saying goes: hello, reach, throw,
tow, row, go, helo (helicopter).

Hello – encourage the victim to swim to
safety. Point positive e.g. point them to

Reach – attempt to get the victim out of
the water by reaching them a paddle
Throw– throw them a flotation or a throw
Tow – tow the victim to shore or to the
boat with a throw bag.
Row – row out to get the victim.
Go – if you feel confident you can initiate
a rescue safely, as a last resort, go out to
get the victim.
Helo – get help for the victim and yourself
from other boaters or by calling search
and rescue.

Native Montanan Josh Olsen
(WEMT) is a lead instructor
for Aerie backcountry
medicine, a ski patroller and a
whitewater rescue technician.
He lives in Bozeman.

Upcoming Events

september, 2022

Filter Events

No Events