Open Water & Pool Coaching Videos

Cold Water Shock

This is the result of our bodies natural reaction to entering cold water.  As we enter the water, our body enters into fight or flight mode. This can be extremely dangerous. The water temperature doesn’t have to even be that cold, the same effect can occur in swimming pool temperature water (I’m sure we’ve all experienced this) so don’t be surprised if you experience it in UK water temperatures, whether it be sea, river or lake!

Cold water instigates a significant respiratory and cardio response. On entering the cold water our heart rate increases considerably as do our respirations but it is known that even our first breath can be enough to introduce a lethal dose of water to our lungs, as the gasp reflex occurs .

May and June  can be the most dangerous time of the year don’t make the mistake of thinking this is a risk only known to winter swimmers!

Stages to cold water shock to be aware of:

 A gasp for breath followed by rapid breathing (hyperventilation) so you are unable to hold your breath under water for more than a few seconds.

As your breathing becomes uncontrolled, your blood pressure will shoot up as your body tries to keep you blood warm by moving it toward the middle of your body (this is why you go pale when you are cold).

The effect of cold water in your ears can induce vertigo so you can easily become disorientated.

Once you gain control of your breathing you can safely exit the water or swim if you are safe to do so.  As your muscles cool your muscle control reduces and you may find you can’t swim any longer and are unable to rescue yourself.  At this point you are in what is known as ‘swim failure’, this is an emergency situation if you are still in the water without any kind of buoyancy aid you are at great risk of drowning.

photo by Ian @greystorm

Your Initial response is absolutely vital to your survival as the initial effects of cold water can pass in less than a minute.

If you intend to go in the water for a swim:

Don’t swim alone or at least have someone spotting from shore

When you first go in  enter the water slowly, don’t jump straight in, stay  afloat keep your mouth away from the water and get your breathing under control and acclimatise

If you go in regularly you will habituate to the cold water after time so it will get easier, but be aware that one day you may feel fine and the next you may not

You need to gain control of your breathing so try to relax and get your breathing back into a rhythm

Wear specialist protective clothing such as a wetsuit, ear plugs, hats etc to reduce the cold water effect

If you are in a situation where a life jacket is required please wear one eg.SUP/ Kayaking


Please watch the video below by Prof Tipton on Cold water shock – the facts | Royal Life Saving Society UK ( RLSS UK )

©Solent Swim School 2022