Heatwave: Police believe boy, 14, has drowned after swimming in River Thames in Richmond

The emergency services searched for the teenager for two hours but the police concluded “the young boy has died”.

A 14-year-old boy is missing and feared to have drowned in the River Thames after going swimming amidst the sweltering heatwave.

As the temperature hit 37.4C, police officers were alerted that a teenager had entered the water at Tagg’s Island in Hampton, Richmond, at 4.43pm.

Emergency services - including the London Ambulance Service and the London Fire Brigade - scrambled to the scene.

Tagg’s Island, top right, is where the teen boy went missing in the river. Credit: Adobe Stock

Members of the public took part in the search for the boy, however sadly the rescue mission was called off at 6.40pm.

Scotland Yard the boy “is believed to have drowned after getting into difficulty”.

Efforts to recover the teenager’s body will continue into the evening.

His next of kin are aware and are being supported by specialist officers.

Supt Richard Smith, from the South West Command Unit, said: “Despite the very best efforts of all involved, we must now sadly conclude that this young boy has died.

“His death is a tragedy and I cannot begin to imagine what his family will be going through. All our thoughts are with them.

“I know that on days like today when temperatures are at a record high, it might look appealing to jump in and cool off in rivers, reservoirs, lakes or other open water.

“Please don’t. The dangers are real and this evening in Richmond we have seen the terrible consequences of what happens when it goes wrong.

“To young people in particular, I would urge you to be the person in your group of friends who says no and reminds others about the dangers.

“Your intervention could save a life and save another family from experiencing such an awful loss.”

There were nine accidental drownings in London last year, making it the joint third highest in the UK, despite not having a coastline.

Earlier in the month, another teenager died after swimming at the lake in Fairlop Waters, Redbridge.

The London Fire Brigade warned before the heatwave about the risk of cold water shot, despite the sweltering temperatures.

Charlie Pugsley, Assistant Commissioner, said: “No matter how hot things get, the brigade is reminding people to think carefully before diving into water.

“Sadly, crews were called to nine incidents in the past year where someone died due to accidental drowning.

“With a sizzling six-week long school holiday ahead we want people to enjoy their summer by swimming in designated safe swimming areas while also warning people about just how easy it is to get into difficulty.

“There is the risk of cold water shock, which can cause your body to go into shock no matter how fit you are. It causes panic, anxiety, disorientation and loss of muscular control, which cause you to gasp for air and as a result, inhale water.”