Cold water shock
Cold water shock, also known as cold water immersion or cold water immersion response, refers to the physiological and psychological reactions that occur when a person suddenly enters very cold water.
Any water below 15°C is defined as cold water. Wild swimmers should always be cautious when attempting to get into water below this temperature and go in slowly to adapt. The average UK water temperature is just 12°C and rivers, lakes and lidos are even colder so it’s very important to be aware of cold water shock and make steps to minimise the risk.
Cold water shock can be extremely dangerous and may lead to various immediate reactions, including:
Gasping and Hyperventilation: When the body comes into contact with cold water, there is a reflexive gasping response. This sudden inhalation of cold air can lead to hyperventilation, making it difficult to breathe and increasing the risk of inhaling water.
Increased Heart Rate and Blood Pressure: The shock of cold water can cause a rapid increase in heart rate and blood pressure, putting additional strain on the cardiovascular system.
Muscle Contraction: Muscles may contract involuntarily, leading to a loss of coordination and the potential for drowning.
Decreased Dexterity: Cold water can numb the extremities, making it difficult to grasp objects or swim effectively.
Reduced Cognitive Function: Cognitive impairment can occur due to the body's stress response, making it harder to think clearly and respond to the situation effectively.
Increased Risk of Hypothermia: Prolonged exposure to cold water can lead to hypothermia, a potentially life-threatening condition where the body loses heat faster than it can produce it.
The Gasp Reflex
Gasp reflex is an involuntary gasp where breathing rate can increase as much as ten times. This causes panic and an increased chance of inhaling water directly into the lungs. These are more likely to happen if you fell, jumped, or ran into the water very quickly so that’s why swimmers go in very slowly and adapt over time to the temperature to minimise and prevent cold water shock.
How do you deal with it?
As you enter the water, go in slowly, splashing water on your shoulders, back of the neck, and chest before immersing yourself gradually.
Pause for a moment When you’re fully in the water pause for a moment and wait before you swim. Stay within your depth and wait as cold water shock will pass in less than a minute. Even if you don’t experience much of an increased heart rate and breathing rate it’s good to take a minute to be aware of how your body feels before you swim.
Float and stay calm If you’re out of your depth then always remember that you can float on your back and catch your breath. Try to relax and open up the body in a starfish position and try to stay calm.
If you struggle with cold water shock:
Wear a floatation device Wearing tow float can be really useful. This is a type of safety buoy you can wear when you swim. See here for a tow float I recommend: HERE
Wear Neoprene Wearing gloves and boots and even a neoprene swim hat are also ways to protect yourself when going into cold water. Here are my recommendations:
Gloves: HERE
Boots: HERE
Neoprene Hat: HERE
One of the biggest risk factors to open water swimming is the cold. Learning how to deal with it is important. Wild swimmers gain adaptation over time to the cold, but it’s always important to be cautious when going into cold water and going in slowly is key.