Swimming in cold water can help increase your metabolism, improve your circulation and reduce stress.

However, it can be very risky - if your body temperature drops below 35 degrees Celsius (a condition called hypothermia) you need to get to hospital immediately.

5 ways to avoid hypothermia

1. Bring a friend and spot the signs before it gets serious

Keep an eye on each other - if someone has slurred speech, pale skin, slow breathing or seems tired and confused there's a high chance they're hypothermic.

2. Bring dry clothes with you

After your swim, make sure to change into warm, dry clothes. Wearing a wetsuit while swimming is also a plus.

3. Drink something hot/ bring a flask

Avoiding hypothermia is all about internal body temperature. Having a non-alcoholic hot drink will help hugely - avoid trying to warm yourself up with a hot water bottle, hot bath or any external heat source, and don't rub your limbs as this will make it worse.

4. Get indoors

Being indoors or under a shelter will help protect you from the elements.

5. If it's not working, call for help

If there's any chance that someone's in danger, call 999. Make sure to stay with them and keep them talking - don't let them lose consciousness.

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