Cold Water Shock
Cold water shock is an involuntary physiological response that can occur when someone is suddenly immersed in cold water. It can happen when someone deliberately enters the water quickly (e.g. by jumping in) or if they fall into the water unexpectedly. It can happen to anyone, even strong swimmers.
Cold water shock is very dangerous and can lead to drowning extremely quickly – it causes gasping, hyperventilation, panic and loss of swimming ability. It can also cause heart rate and blood pressure to spike, which can cause a heart attack, even if the person is fit and healthy.
Water is considered dangerous for cold water shock when it is 15°C or below. Open water like the sea, lakes, rivers and reservoirs can remain at this dangerously cold temperature all year round in the UK, even during heatwaves and period of hot weather.
Safety advice
- Learn about the dangers of cold water shock. Cold water shock occurs when someone is suddenly immersed in cold water. It’s an involuntary response that causes gasping for breath, increased strain on the heart, panic and loss of swimming ability, which can sadly lead to drowning.
- Just because the weather is warm, it doesn't mean the water will be. Open water in the UK can remain dangerously cold all year round, even in summer. Both the sea and inland bodies of water like lakes, reservoirs, canals, rivers and lochs can remain at 15°C or below all year round in the UK, the temperature at which water is considered dangerous for cold water shock.
- Swim at a lifeguarded beach or open water swimming site. If you're planning on swimming, choose somewhere with lifeguards so there is a trained professional on hand to help you if you get into trouble.
- Enter the water slowly to acclimatise – cold water shock occurs when somebody enters the water too quickly, either by jumping in intentionally or by falling in accidentally. By entering the water slowly and steadily, you give your body time to adapt to the cold, reducing the dangers of cold water shock.
What to do in an emergency
If you find yourself in trouble in the water or think you might be experience cold water shock, Float To Live:
- Lay back with your ears submerged under the water
- Try to relax and breathe normally
- Move your arms and legs to help you float - don't worry if your legs sink, everybody floats differently
- When the shock has passed, shout and signal for help, or swim to safety of you can
- Practise your float in a safe location like a swimming pool or lifeguarded beach
If you see someone else in trouble in the water, remember to Phone Float Throw:
- Phone 999 to get help
- Tell the person in the water to stay calm and float on their back
- Throw rescue equipment to help them float until the emergency services arrive