Hunstanton swimmers have been dipping on Christmas for 50 years
The warmest of summer days can still fail to tempt some beach-goers into the sea for a dip.
So spare a thought for those braving a plunge in the cold North Sea on Christmas Day to help raise money for charities in Norfolk and Suffolk.
Last year in Lowestoft the Christmas Day bathers raised £10,000 for good causes while their counterparts in Hunstanton, Norfolk collected nearly £4,000.
This year marks 50 years of mid-winter
madness in Hunstanton, and members of the Hunstanton and District Round Table, which organises the event, hope to attract record numbers into the sea.
Round-tabler Andrew Searle said: "We were looking at the dates of the swim and we found that it was first started by the Seagulls swimming club on Christmas Day 1947.
"They decided that they would go to swim in the sea on Christmas Day.
"Originally there were more people that were going to go in than actually did because a number of them suddenly called off at the last minute, with only four going in out of the original eight."
About a hundred miles along the coast at Lowestoft, bathers were also set to dip more than their toes in the waters for Christmas Day charity fundraising.
But organiser Lawrence Chapman, 38, said the temperature of the North Sea - about 6C - was relatively mild compared to temperatures in February or March when it reaches its coldest.
Lawrence Chapman has swum on Christmas day for the past 20 years
He will be celebrating the 20th anniversary of his first dip.
"Thinking about it is a lot worse than doing it," he said.
"But then I often wonder if that's a bad thing to say because people might not sponsor us so well.
"The swim is all about preparation, warming up on the beach is a must and you need to wear shoes for a run on the beach, because if you don't do that you'll be frozen from the start.
"The other piece of advice is you mustn't dive in because the cold water hits your forehead and tends to make you a bit dizzy."
Back in Hunstanton, Andrew Searle said he would not be among the swimmers.
He said: "It's a bit difficult to go in when you are organising the event.
"Besides, someone has to go round the beach with the buckets to collect money from the crowds that are watching.
"I have swum. When I was chairman of the round table it was part of the rules that you went in.
"The way it works is that the chairman and the vice-chairman carry the banner that leads the swimmers down to the sea and of course you have to go in."
Christmas day swim before Hunstanton pier was demolished
Both organisers agreed there was a strong camaraderie among the swimmers, and a lot of support from the spectators.
Lawrence Chapman added: "The actual swim is over and done with in about ten minutes or less so to get £10,000 in that space of time is great.
"There's a lot of harder ways to raise that kind of money.
"The charities write in for the money and they are doing a fantastic amount with just £500 or so each, and it's good to see how much they are helping people in Lowestoft and the Waveney area."