A swimmer has been missing since Tuesday afternoon after getting into difficulty in the water as 14 people have died over the past week during the UK's heatwave.
Five others were pulled from the water after a "serious" incident close to Clacton Pier, it was reported.
HM Coastguard told the BBC they were responding to "a report of multiple people in the water", saying: "Five people have been rescued, with the search still ongoing for a sixth male."
A 14-year-old schoolboy's body was recovered on Tuesday from the River Thames after police feared he had drowned the day before.
In Blackpool, a 14-year-old boy is said to be in critical, but stable condition and a 12-year-old boy is said to be "poorly" after they were pulled from the water near Central Pier.
Brits are being urgently warned about the dangers of trying to keep cool amid the record-breaking temperatures after several tragedies in open water and reservoirs over the past week.
The Met Office issued its first ever red warning for exceptional heat in parts of England, saying it expects "population-wide" health effects that could "lead to serious illness or danger to life".
And newly appointed Health Secretary Steve Barclay warned of "significant dangers" for people tempted to swim in a river, urging those venturing outdoors to use "common sense" and follow the advice of public health experts.
He added: "There is a particular message, particularly for teenagers, children, some of those who may be tempted to go for a swim - there's significant dangers of that, quite often when people go swimming in rivers when we have very hot weather."
The deaths last night follow the family of 13-year-old Robert Hattersley saying they were "absolutely devastated" after he passed away when he got into trouble in the River Tyne in Northumberland on Sunday.
Emergency services also confirmed the deaths of a 16-year-old boy in Bray Lake near Maidenhead, Berkshire, a 16-year-old boy in Salford Quays, Greater Manchester and a 24-year-old paddleboarder in North Wales.
Four more people - three men in their 50s and a 37-year-old man - died in similar circumstances, while a fifth reportedly collapsed and died of "heat stroke" when playing football at the weekend.
Below is a timeline of the tragic events as they unfolded in recent days.
Monday, July 18: Four drown and schoolboy's body found in River Thames
Police were called shortly after 6pm to Cotswold Water Park, and said a man was confirmed dead shortly after being pulled from the water.
His death is not being treated as suspicious.
At just before 5pm, the Met Police were alerted by London Ambulance Service to reports that a 14-year-old boy had entered the water at Tagg's Island in Hampton, West London.
The Metropolitan Police said the body recovered at around 3.30pm on Tuesday was believed to be that of a teenage boy who was seen entering the water on Monday afternoon.
He was locally named as Brian Sasu as his father told the MailOnline: "Brian could not swim, he hated being in the water. He only liked playing football and never showed any interest in any kind of water sports.
"We are all devastated, this is like a nightmare. At the moment, we are waiting to hear more details from the police. This is a very difficult time for us."
Just after 4pm, a body of a man in his 60s was found in the River Irwell in Bury, Greater Manchester Police said.
A spokesperson for Greater Manchester Police said: "At around 4.05pm this afternoon (18 July 2022), police were called to a report of a concern for the welfare of a man in the water near Jubilee Way, Bury. Emergency services attended the scene and sadly a body of a man in his 60s was located.
"There are believed to be no suspicious circumstances. Enquiries are ongoing."
On the Isle of Wight, a tourist in his 70s was pulled from the water unconscious in the water near Sandown Pier, at about 5pm on Monday.
Ryde Beach Lifeguards said he was pulled from the water, but despite their best efforts he was declared dead at the scene.
The lifeguard team said: "Our sincerest condolences go out to the gentleman's family and friends."
Earlier on Monday, Thames Valley Police confirmed a 16-year-old boy had died after getting into difficulty in Bray Lake, near Maidenhead, Berkshire.
Officers were called at 11.45am and a body was located at just after 1.30pm, said the force. He was pronounced dead at the scene.
On Tuesday, he was identified as Sean Norbert Anyanwu as his family released a statement via police.
His family said: “Sean Norbert Anyanwu was the light of the family and he was everything we could have asked for.
“We are devastated by his loss and we would ask for our privacy to be respected while we grieve.”
Danny Edwards, Sean's headteacher at Cox Green School in Maidenhead, said: "With the deepest sorrow, we have learned that one of our Year 11 pupils, Sean Anyanwu, passed away yesterday at Bray Lake after getting into difficulty in the water.
"Sean was a kind-hearted pupil with a close friendship group and had worked tirelessly in his recent GCSE exams to achieve his very best."
Sunday, July 17: One teenager and two men die in the water, and another 'dies from heat stroke'
Robert Hattersley, 13, died after getting into trouble at the River Tyne near Ovingham in Northumberland.
Emergency services rushed to the scene at around 4.15pm.
Police officers, firefighters and rescue workers searched for Robert and his body was found in the water shortly afterwards.
In a statement, Robert's family said: "It is impossible to put into words the heartbreak we are feeling – Robert was so kind and loving. We are absolutely devastated by what has happened.
"He brought a smile to so many people’s faces and he will be missed by absolutely everyone who knew and loved him.
"We’d like to thank all the emergency services who worked so hard to try to find Robert, as well as everyone who has been in touch passing on their messages of condolence."
A 51-year-old man, named locally as Stuart Bailey, also died after his kayak capsized on the River Morey in Scotland.
A post on his personal Facebook page said: "It is with great sadness to inform you that yesterday at 4pm 17th of July 2022, Stuart Bailey tragically lost his life in a canoeing accident on the Spey River where he was surrounded by friends.
“We are sending love to all of his friends and family during this shocking time, this is a great loss for all and he will be dearly missed.”
Police said inquiries were ongoing to establish the full circumstances.
Another man in his 50s died after falling from his boat and getting into difficulties in the water in County Kerry, Northern Ireland.
And another man, who identity is yet to be confirmed, died after reportedly collapsing from heat stroke amid extreme temperatures in East London.
He was playing football on a pitch in Cubitt Town, Tower Hamlets at the time, reported MyLondon.
Saturday, July 16: Teenage boy and three men die after getting into difficulty in water
Kalen Waugh, 16, drowned after taking a dip with friends in Salford Quays, Manchester.
Greater Manchester Police confirmed his death is not being treated as suspicious, though formal identification is yet to take place.
GMP said the teen's body was located on Saturday evening following a major search operation, before being recovered overnight.
On Sunday, flowers and balloons were left among tributes at the scene, with one reading: "RIP Kalen".
Headteacher Almut Bever-Warren told the Mirror: "Kalen was a very popular student with us, he had a college placement for September, mum was very proud of him that he had sat his GCSEs, the first in the family."
Police were also called to Ardsley Reservoir in Wakefield, near Leeds after reports of a man getting into difficulty in the water at around 5.30pm.
The body of a 50-year-old man was recovered the following day after a 24-hour search.
And a 37-year-old man was rushed to hospital after emergency services were called to a medical incident on Brighton beach, shortly after 7pm, but sadly died.
Sussex Police said: "There are no suspicious circumstances and a report will be prepared for HM Coroner."
On Saturday afternoon, an experienced diver died while swimming off an East Lothian beach.
The 48-year-old man, from Edinburgh, was with his brother when he got into difficulties, EdinburghLive reports.
A police spokesperson said: "Officers attended at Tyninghame Beach near Dunbar at around 4.20pm on Saturday, following the sudden death of a 48-year-old man.
“There are no suspicious circumstances and a report will be sent to the Procurator Fiscal.”
Thursday, July 14: Young woman dies in paddleboarding tragedy
Emma Louise Powell, 24, passed away in Conwy Morfa, North Wales, after she and two other paddle boarders got into difficulties at the popular beauty spot.
A major search and rescue operation for the trio was mounted which involved the RNLI, the police, ambulance crews, and a coastguard helicopter.
All three people were rescued from the water, but Emma tragically died in the early hours of the morning.
In a statement, her family said: “Emma was a beautiful young lady, who was adventurous and had a free spirit. She will remain in our hearts for the rest of our lives."
