For thousands of people up and down the coast, a festive dip in the sea is part of a Christmas tradition.
Boxing Day Dips are taking place up and down the North East coast - but before you take the plunge, the RNLI has issued some tips to help you stay safe in the water.
The best way to avoid cold water chock when taking part in a dip is to wear a wetsuit.
If this isn't possible, the charity is encouraging people to walk into the sea slowly and stay shallow to allow your body to acclimatise to the temperature.
Nick Ayers, RNLI Community Safety Partner, said: "The festive dip is now a firm family favourite in the calendar as many brave swimmers take the plunge year after year with their families and friends over the holidays.
"As the charity that saves lives at sea, we want to remind people that over winter the sea is at its coldest!
"We hope all enjoy the water, but are also aware of what do to if they or their fellow swimmers do get into trouble.
"Before going in, we urge people to remember the risks of cold water shock and what to do if it happens to them. The simple act of floating could save a life."
What to do if someone is suffering from cold water shock
Cold water shock causes uncontrollable gasping, which increasing the risk of you swallowing water and puts a strain on your heart. In extreme cases it can cause cardiac arrest.
If you're suffering from cold water shock, the RNLI says you should fight your instinct to thrash around and swim hard, instead just lie back and float.
The initial shock will pass within 60–90 seconds, and when you have regained control of your breathing, you can then try swimming to safety or calling for help.
This skill will give you a far better chance of staying alive.
Nick added: "I am taking part in the dip myself this year, making sure I’m part of an organised event and that I stay in a group.
"We encourage those who plan on taking part to join a scheduled event, as they will be in good company with other swimmers, as well as safety staff."
If you see someone else in trouble in the water, fight the instinct to go in yourself. Call 999 or 112 and ask for the coastguard.
Where you can take part in a dip this year
Berwick: 11am at Spittal Beach in aid of Mayoress' charities
Hartlepool: 11.30am from the Marine Hotel, Seaton Carew
Newbiggin by the Sea: 11am from the promenade adjacent to Bridge Street on the seafront
Redcar: 11am at Dundas St Slipway. Those wishing to take part should register at The Hub, Esplanade, Redcar on Boxing Day from 10.15am.
Seaham: 11am at Seaham Harbour Marina
South Shields: 12pm at Little Haven beach in aid of St Clare's Hospice
Whitley Bay: 11am from the North Sea Volunteer Lifeguards HQ on Tynemouth Longsands