Two men have died after going into the water in a rescue attempt at Seaton Carew beach, Hartlepool.
They were trying to help two children who had got into difficulty, Cleveland Police said.
Both children are safe and have been taken to hospital to be checked over.
Police were called to the scene at around 3.45pm on Sunday and officers attended with the RNLI, Coastguard and North East Ambulance Service medics.
The two men were brought out of the water by the RNLI and were given medical treatment but were pronounced dead a short time later.
Superintendent Glen Ward said: "Our deepest sympathies go out to the families of both the men involved in this tragic incident today.
"Despite the best efforts of emergency services, sadly both men were pronounced dead a short time after being brought out of the sea.
"We are conducting enquiries into the circumstances of what happened today, although the deaths are not being treated as suspicious and a file will be prepared for the coroner.
"I would like to remind everyone that open water comes with serious risks. We know it is inviting in the hot weather, but we would encourage people to refrain from entering any open water at all. Today we have sadly seen the true tragedy that can happen as a result.
"Please take extra care and enjoy the warm weather as safely as possible."
They are the latest in a spate of open water deaths this summer during successive heatwaves.
During the May heatwave, at least 15 people, mostly children, drowned while swimming in open water.
On Friday, two 18-year-old men died in separate incidents at Dovestone Reservoir, Oldham, and the Darley Abbey Mills complex, in Derbyshire.
Amber alerts issued by the UK Health Security Agency (UKHSA) for the West Midlands and South West, and yellow alerts for the East Midlands, the North West, the South East, the East of England and London, are in place until 9pm Wednesday.
The UKHSA said significant impacts are likely across health and social care services and warned of a potential increase in water-related incidents across England, including risks from risks from cold water shock and drowning.
(c) Sky News 2026: Two men die after going into sea to save children at Seaton Carew beach, Hartlepool
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