Before attempting a cold water swim please seek the advice of a medical professional.
This presentation is collected from my own documented experiences and research into
cold-water swimming from various sources including discussions with my physician who
is also a swimmer and triathlete, and part of my support team.
The information presented is meant as a starting point for your own research and
training. Do not attempt cold-water swimming before seeing your doctor and getting a
full medical check. I’d also recommend speaking to a swim coach and/or personal trainer
to ensure you are fit and have learned to recognise your own body’s warning signs.
”Toughest Swimming Challenge Ever.”
~ Sally Goble, The Guardian
An ice swim is a swim in water that is 5°C or colder wearing nothing but a swim suit, cap
and goggles. By it’s extreme nature it is not for the faint hearted and not for everybody.
But many people are now taking up the challenge of what has been described by Sally
Goble of the Guardian Swim Blog as the toughest swimming challenge ever.
If you are thinking about training for an ice mile, think again. Think very carefully. Weigh
up all the risks and DO NOT take the challenge lightly. This is not something that can be
done by just turning up and hoping for the best.
Many months (or even years) of acclimatisation, training, planning and preparation will
need to take place and even then nothing is guaranteed.
Here are some things you need to consider before stepping into the water
Swimming in cold water is an extreme environment to put yourself in and there is no
getting away from the fact that hypothermia can kill you. You should therefore be aware
of ALL of the health risks before you even start training for an ice swim.
Hypothermia is the obvious danger but blood pressure, heart and respiratory rate will be
vastly increased during cold exposure. If the re-warming isn’t managed very carefully you
risk a severe decrease in blood pressure and increased risk of heart attack.
Have you had a full health check including an ECG? Get one!
Speak frankly to your doctor about what you want to do and make sure they fully
understand what you want to train for. They are the experts when it comes to your health.
How do you plan to prepare yourself for an ice swim?
• Ice baths, repeated cold water swims?
• Where will you train?
• Who will you train with?
• Do you have a progressive training plan?
• Who will supervise you from the shore/beach?
• Do they know what to expect and how to treat you?
• Do you have a rewarming/recovery plan in place? Develop one over several months and
once you find what works for you stick with it.
Do you know the rules for an official International Ice Swimming Association (IISA) ice mile
swim? There are rules for every aspect of the swim. Read them. Read them again and
again. Ask questions until you and your support team are fully aware of the requirements
for official IISA recognition. You don’t want your swim to be disqualified for missing a tiny
• Is the swim to be a point A to point B route, or laps?
• What is your go/no go criteria?
• Is the entire shoreline along the route accessible to your support team?
• Are they able to follow alongside you?
• How far from shore will you be swimming?
• Will you need boat support?
• Is the entry into and out of the water via sand, rocks, gravel, boat ramp, or ladder? Walking
barefoot on rocks and gravel can be painful in the summer months. You can multiply that
pain many times when walking on these kinds of surfaces with frozen feet. Ladders will be
almost impossible to climb up with cold hands and tired muscles.
• What contingency do you have in place if you have to abort the swim part way through and
exit the water at an unplanned point? Multiple sets of towels and clothing along the route,
cars parked at various points en route? The short of it, have a plan B and make sure
everybody understands it.
• How well do you know the location?
• Have you swam here before?
• Have you trained here with your support team?
• Is there cell phone service?
• Is the location easily accessible to the emergency services?
You may be the only swimmer in the water but nothing is possible without a support team.
• Choose your team very carefully, many people may be willing to help but not all of them
will be capable of doing what is required. At an absolute minimum you will need: Medical
supervision, kayak/boat crew, land-based recovery crew.
• Do you trust each person implicitly to perform their assigned roles?
• Do they know you as a swimmer? Strange question but can they recognise your natural
swim stroke and rhythm well enough to spot the early signs of any problems in the water.
They will most likely detect problems before you realise you are in trouble.
• How many people do you need to help you achieve your goal?
• Have you trained with your team?
• Do the team know the rewarming/recovery plan?
• Who will dress you once you exit the water?
• How will they dress you and what clothes will you wear?
• During the swim and recovery their sole focus should be you. Do they know what to
expect from each other and you at all times
I begin my acclimatisation in the autumn and use several training locations which I know
very well. I am very careful to monitor and record the water temperature, my pre and post
swim core (rectal) temperatures and swim times. Swim times can range from just a few
minutes in January and February, the coldest months, to over an hour in October and
I am always supervised during my training sessions and at times I have had a support
team of up to 6 people. They have been fully briefed on what to expect from me during a
swim and once I exit the water. I am dressed by the same person, in the same clothes and
in the same order each time.
We dress the upper body first to protect the core temperature and only once I am in
multiple layers with hot water bottles stuffed inside my jacket do I then dress my legs and
feet. At this point I am also taking on warm drinks to help rewarm from the inside out.
During the short drive home I continue taking on warm drinks while the heat is on full
blast in the car. Once home I complete the rewarming process in the shower. Starting with
cold water and over a 20-30 minute period gradually increase the heat of the water.
Over the past two winters I have learned a lot about myself and what I am capable of with
the correct preparation and support. My extreme cold water swims include:
4.33°C, which was recognised by the IISA as Canada’s first official ice swim.
Along with many shorter swims at water temperatures as low as 2.33°C.
I am the Canadian Ice Swimming Ambassador for the IISA.
Happy swimming, good luck and most of all stay safe.
My own experiences are documented on my website
International Ice Swimming Association (IISA)
IISA Country Ambassadors
International Winter Swimming Association
Written by Paul Duffield, Canada’s first official ice swimmer
Photography + Design by Angelique Duffield