This is the second in a series of three about the basics of what can happen to your body when you swim outside. It’s based on years of experience as an outdoor swimmer, coach and wild swim guide. This blog talks about swim failure, a potentially scary phenomenon associated with getting cold whilst swimming.
Swim failure, also sometimes referred to as cold incapacitation and stealth chilling, can be a sneaky wee bugger. It’s something that often goes amiss in safety advice, overshadowed by the much talked about cold water shock which I covered in the first of these posts here. When I bring it up I often see people’s faces drop “You mean there’s something else after cold water shock?”. Yes, but as with everything in life it’s a risk which, with understanding, can be managed very effectively and easily.
So, what is swim failure?
Water can conduct heat on average 25 times better than air. Any water below body temperature (37C) has the potential to cool us down. How quickly that happens does depend on the water temperature, you’ll cool down quicker in 5C water than 20C water but, cooling’s still happening albeit more slowly. This is what causes swim failure.
Our body’s have an optimum temperature for all of our systems to function, going only a few degrees either side of that can lead us to shut down. Our bodies are very clever though. As we cool, our body restricts blood flow out to our extremities (arms and legs) to reduce heat loss and keep the vital organs in our core working. If blood flow is restricted to our muscles, they’re not getting oxygen or fuel so they won’t work as well. Think how stiff or weak your fingers might go on a cold day.
We use our arms and legs to keep us afloat and moving in the water. If the muscles out there aren’t getting the oxygen and energy they need they won’t work, we lose strength and our ability to coordinate. We lose our ability to swim back to shore, even to float and keep our heads above water. I think you can all see where that’s heading. This is swim failure.
I often refer to this kind of tragic headline to put it into context “They were a strong swimmer, I just don’t understand why they didn’t make it back from the middle of the lake”.
It doesn’t matter how strong a swimmer you are, if your arms and legs aren’t getting what they need to work you can’t swim.
Scary, sad, tragic right?
Yes, unquestionably, but it’s something that can be really easily avoided and getting to that headline stage is very rare.
So, how do you avoid swim failure?
Learn about your own body. What it can cope with, how it’s affected by the cold, how high a tolerance of the cold it has. It can be a slow process, hence the term stealth chilling, it doesn’t suddenly happen like cold water shock, it gradually builds so make sure you’re constantly checking in. If you’re in a group it’s easy to forget, get distracted, be pushed by that gentle peer pressure but try and check in with yourself as often as you can.
Notice when your limbs start to feel heavy, if your hands start to “claw”, if your swim stroke has changed or your body position in the water’s dropped. Look out for these things in others too. I can spot when my regular swim bud’s starting to feel the cold, her stroke changes, she slows down, everything just looks a bit harder. Sometimes it’s tiredness but never forget that tiredness can happen more quickly too due to the energy demands of keeping warm. Remember your body is your own, heavy limbs and clawed hands are good signs but yours might be different. You do you.
My golden phrase is “get out feeling like you could do more”. This way you know you’re safe. This doesn’t mean you should never push to swim further or for longer but do that carefully and in small increments. If you feel OK when you get back to shore, try another short swim and see how you feel. Maybe think about staying closer to shore or within standing depth until you build confidence and knowledge of what your body can do.
And always remember it’s not just the water temperature that counts. The air temperature and weather play a huge part too. As does your state on the day, being tired, stressed, hungover, hungry, all manner of other you factors play a part in how you fare.
What should you do if you start to feel like this is happening? Get back to shore as soon as you can and get out. Bear in mind that if your limbs weren’t working too well in the water they’ll still not be working well on land so be careful as you get out. You might stumble, be wobbly and find it difficult to hold onto things for support. Get dressed as quickly as possible and get warmed up. You’ll carry on cooling after you get out too so bear this in mind but that’s for another day and another post on afterdrop here XX
I hope that was useful and please don’t let this put you off the joys of outdoor swimming, it’s all easily managed with the right knowledge and care……….just like most things in life.
Happy swimming x