Winter dips – cold water benefits and safety
On a rather gloomy day, 10 December 2023, a small group of swimmers met to have a walk and a cold water dip and to call for a Right to Swim in Bawsey Lakes at any time of year. Although some think that swimming in winter is a rather odd habit, we know that there are many benefits, and that it can be done safely with a little knowledge. This post answers some questions about winter dipping and give some tips.
We had a lovely refreshing dip at Brickyard Lake, in 5° water on a fairly mild day, kept warm by our Christmas swim or bobble hats, and afterwards shared some mince pies. The park warden attended and a couple of us had a pleasant chat with him. We then had a walk round to the Great Lake, and its beauty and size impressed those swimmers that had never seen it, even on a grey day. (That lake was 5.5°, pH4.5.)
We met to dip for fun and to call for the Right to Swim – as outlined by Right to Roam https://www.righttoroam.org.uk/ we need a right to responsible access to land and water, as in Scotland – and to support The Outdoor Swimming Society’s Inland Access Manifesto calling for freedom to swim. Read more about Wild Swimming and Access. To show that we need more access to swim, we swimmers Go Swimming! (Or more probably have a quick dip at this time of year!)
Cold water swimming and winter dips are growing in popularity. This includes a long tradition of festive dashes into the water and regular swimming by increasing numbers of keen enthusiasts including some who even break the ice on the coldest days.
SOME QUESTIONS AND SAFETY TIPS
Jump to Q&As below:
Why would you get into cold water, especially in winter?
The benefits are becoming widely known and increasingly studied. Not all are proven yet, but there is much evidence for a wide variety of physical and mental health benefits along with the fun and challenge the activity gives.
Why do you want to get in a lake (including lakes that were previously quarries or reservoirs)?
In winter rivers can often be flooded, fast flowing, silty and potentially polluted after heavy rain. The sea can be rough and also potentially polluted. Lakes rarely have any of these issues, and have far fewer risks. The Bawsey Lakes were once excavated for sand, but now are filled with water and behave in the same way as any other water body of a similar size.
Which water bodies are colder in winter?
The sea retains its warmth longer into the autumn and winter than other water bodies. Rivers vary considerably because of their size, proximity to the source, how fast they are flowing, how much sunshine has warmed them. Lakes cool down once the sun has little warmth or time to warm them up, plus the cooler layers of water can come to the top and cool air can cool the surface, and once they cool down then they can stay colder throughout the winter. In spring they warm up again and retain that warmth during summer. Larger lakes change temperature more slowly. The wind might be a bigger factor when there is less shelter – be aware of air temperature, especially when getting dressed or undressed.
How can you stay safe swimming in winter?
Key tips – don’t get too cold, and get warm quickly afterwards.
- avoid cold water shock by getting in gradually
- stay close to shore unless experienced in cool water
- don’t stay in too long
- get dry, dressed, warm as soon as you get out of the water.
More safety info on the Outdoor Swimming Society website: https://www.outdoorswimmingsociety.com/tips-on-winter-swimming/; and https://www.outdoorswimmingsociety.com/category/survive/cold/
How long should you stay in?
Everyone is different and there is no simple formula – each person needs to get to know their own body. An important thing to know is that there is no need in winter to stay in more than a few minutes – almost all of the benefits come from that initial period. If well acclimatised and you want to stay longer you can, but risks increase the longer you are in very cold water.
Watch and listen to cold water swimming experts explaining the risks and benefits and why the first few minutes matter most:
- Heather Massey – listen to ‘Just One Thing’ with Michael Mosley, 2023, 15 mins, https://www.bbc.co.uk/sounds/play/m001t9jt?partner=uk.co.bbc&origin=share-mobile
- Prof Mike Tipton – listen to ‘Sliced Bread’ about cold tubs and outdoor swimming, 2023, 28 mins, https://www.bbc.co.uk/sounds/play/m001s5hc?partner=uk.co.bbc&origin=share-mobile
- Dr Mark Harper – video of talk on YouTube, 2017, 8 mins, https://www.youtube.com/watch?v=0pXLF0sucDU
- Read Dr Mark Harper – ‘Chill: The Cold Water Swim Cure’ (available from bookshops including Waterstones)
- Watch Dr Mark Harper on YouTube outline the stories and info in the book Chill, 2022, 3 parts (17, 22, 22 minutes, safety tips at 6 minutes in Part 3), https://youtu.be/0-m-kkbdTdQ?si=La75iw26BfEaEoR5; 2, https://youtu.be/Gq6tHRjhYog?si=86rEwKuGxnos35d_; 3, https://youtu.be/j0vQYn1_YKM?si=AcAtIr49ODHriVSS
Will cold water shock kill you in seconds?
In theory it could, if not carefully managed. If someone unused to cold water enters the water too quickly especially head first, this can cause an involuntary gasp, and if your head is underwater when this happens you could breathe in water and drown. The shock of cold water can also increase heart rate, which is not generally an issue unless somebody has a heart condition. Those used to cooler water are less likely to experience this because of acclimatisation, unless the water is much colder than they expected.
Is cold water shock good for you?
Yes, carefully managed, it provides many benefits. This is explained in the four links above – by the three experts on cold water swimming and its risks and benefits. They are all members of the team led by Prof Mike Tipton that are studying this, and there is practical research and training carried in the Chill courses. The benefits include reduced stress in daily life, increased resilience, improved self-image from meeting the challenge, being in the moment, exhilaration. All of this is achieved in the first few minutes of immersion in which you experience cold shock and then it passes.
What are the other benefits of winter swimming?
More generally, cold water immersion helps with depression, inflammation and pain, and there are reported improvements to immune system and hypertension. Putting your face in water triggers the part of the nervous system that makes you calmer. And this is on top of the well documented benefits of blue and green spaces – being in nature – and being part of a community or gaining other social benefits.
In addition, outdoor swimming brings the potential for major improvements in public health, tackling diseases caused by modern lifestyles including physical inactivity. All of this is well explained by Dr Mark Harper in ‘Chill: The Cold Water Swim Cure’, and at a Scottish Parliament Event outlined here, https://www.outdoorswimmingsociety.com/outdoor-swimming-as-a-public-health-measure/and viewable on YouTube here, https://youtube.com/watch?v=iYuJka3xEI0&t=1714s
What should you wear for winter swimming?
Many people swim or dip in just a swimsuit, often adding a swim hat and/or a bobble hat, swim shoes or socks and gloves. (It is a myth that gloves and shoes prevent you knowing you are cold, and they could prevent discomfort and other issues ). Some add neoprene jackets, and some wear wetsuits.
Will a wetsuit prevent risks of cold?
Swimming in a wetsuit does not prevent cold water shock – in fact it can happen when water enters the wetsuit, and if out in a lake that could cause issues including panic, so you need to let some water in before setting off to swim. It also doesn’t prevent you getting cold, it just takes longer. And you need to be able to take it off quickly so that you can get dry and dressed and warm as soon as you can.
What’s the best way to warm up before getting in the water?
Being warm before you get in means that it will take longer to cool down, and the best way to get warm is with some exercise. Perhaps build in a 10-15 minute brisk walk to get to your swim spot, and then again afterwards? Warming up your exterior, say by sitting in a car with a heater full blast, doesn’t warm you as much, and also tricks your body into thinking you are warmer than you are and you cool down more quickly once you get in the water. (This is explained by Dr Mark Harper in ‘Chill’.)
What’s the best way to warm up after getting out of the water?
Always take off wet clothes, get dry, put on lots of warm clothes. Hot drinks are nice but don’t actually do much to warm you up – and be careful not to burn yourself on them!
There are several myths about getting warm after a swim. It’s unlikely that you would have the chance for a warm shower or bath but there would be no harm in doing so as long as you’re careful not to burn yourself, and avoid the very unlikely chance that you might faint. A sauna is a great way to warm up. The best way is to do some exercise – a brisk walk, some star jumps, or whatever you like to do. All of these methods are fine and do not make your core colder. (For an up-to-date explanation on this, see brief explanation and more detail in a webinar with Heather Massey and Prof Mike Tipton, https://outdoorswimmer.com/featured/even-melons-get-afterdrop/)
Can you jump straight in?
It is safer to get in more gradually, because of the possibility of cold water shock, and leave putting your head in until you have got past the shock phase and your breathing has calmed down. Swimmers who are well acclimatised and are used to doing this can jump or dive in – but only do that if you are sure you can.
More info on safety and cold on the Outdoor Swimming Society website https://www.outdoorswimmingsociety.com/category/survive/cold/
What specific risks are there at Bawsey Lakes?
These lakes behave like any other lake, and are cold in winter. Cold is the biggest risk – see all the links and explanations above on how to stay safe. Because entry and exit is very easy on the shallow gradual sandy beaches and there are no tides or currents, it is much safer than the sea or the river in winter, though do be aware of the effect of wind especially in the more open larger lake. The water is deep, so to enter the lake you need to be able to swim, and unless very well used to cool water it’s best to stay near the shore.
Many claims of particular risks have been made for these lakes. We have examined and assessed these as thoroughly as we can and continue to do so, outlined in this article, Risks and Myths at Bawsey Lakes.
Location details: Bawsey Pits or Lakes
There is now a page: Winter Dips – Cold Water Benefits and Safety (Lakes), focusing on these topics alone, https://www.imogensriverswims.co.uk/blog/issues/swim-safety/winter-dips-cold-water-benefits-and-safety/