Cold water shock

The effects of cold water shock are responsible for the deaths of many victims of drowning in the UK every year.

We all know that water conducts heat away from our bodies four times faster than air, meaning as soon as you enter the water, you are at risk of getting cold or hypothermic.  But what is cold water shock and how does it effect us?

Cold water shock can be described as the physical effects of entering cold water and can be observed from temperatures as moderate as 25°c and research has shown that cold water shock can be accountable for a number of strong swimmers who drown in the UK every year.  This is largely due to the victims struggle to maintain a clear airway during hyperventilation, their inability to operate their extremities and the effect of the heart.

What are the stages;

1. Initial immersion responses – Cold shock response (0–3mins)

 Immediately after immersion in cold water, rapid cooling of the skin causes a number of instinctive and reactions including gasping, hyperventilation, restriction of blood flows, and panic.

2. Short term responses – Loss of performance (3–30mins)

 Following the cold shock response, the hands, feet, arms and legs start to cool and blood flow continues to be restricted. This causes a decrease in muscle strength and endurance leading to muscle fatigue and reduced control over body movements. If the casualty is unable to get out of the water or use a buoyancy aid, this will ultimately result in drowning.

3. Long term responses – Hypothermia (30mins+)

 Over time, significant heat lost causes the core body temperature to drop leading to hypothermia.

Protecting myself;

• Avoid sudden entry into water
• When boating, wear correct PPE including a lifejacket
•  When surfing, wear a wetsuit and slowly walk into the sea
• If planning event, consider how to reduce the risk to competitors

•