Emergency services were called out to deal with three young people who went sea-swimming in the early hours of the morning.
A young woman and two young men went into the freezing sea at Towan beach in Newquay at approximately 4am this morning.
A friend of the group is understood to have called the Coastguard after becoming concerned for their welfare.
The Coastguard and Police warned against the potentially fatal consequences of going into the sea after drinking alcohol.
A spokesman for Falmouth Coastguard, who co-ordinated the emergency response, said: “They managed to get out of the water just as the teams arrived. Two were treated at the scene for the onset of hypothermia and one was arrested by the police.”
The Coastguard said they would advise anyone considering going to the beach at the end of a night out “to think twice”.
Graham Thomas, Duty Inspector at Devon and Cornwall Police, said the young woman was initally arrested at the scene for being drunk and disorderly but was then de-arrested when she calmed down.
Mr Thomas said: “It looked like it was high spirits that went over the edge.”
The Inspector warned of the dangers of swimming at night after going out drinking.
He said: “We have had a number of incidents where people have drowned in the sea.
“What may seem like a good idea can turn into a traumatic event. Please don’t go into the sea if you are under the influence of alcohol.”