The UK’s coastguard has issued a new warning urging people to be careful in the sea, after recording its highest number of call-outs in a single day for more than four years.
Its teams dealt with 340 incidents and rescued 146 people on Saturday.
Saturday was the second day of a mini-heatwave for parts of the UK, with temperatures hitting 34.5C (94.1F).
The latest figures come just over a week after the coastguard reported its previous record of 329 incidents.
HM Coastguard’s head of coastguard operations, Richard Hackwell, said there had been “a big rise” in incidents this weekend “as more people visit coastal areas and head to the beach”.
“We understand that people want to have fun at the coast and enjoy the heatwave but we urge everyone to respect the sea and take responsibility in helping to ensure the safety of themselves, friends and family,” he said.
The warning comes as many Britons are facing another sweltering day, with Met Office forecasters predicting highs of 35C in southern England - most likely in Kent, Sussex and parts of London.
As of 16:00 BST, the top UK temperature was 33.5C in Gosport, Hampshire, BBC Weather said.
Highs of 24.3C were recorded in Scotland (Achnagart), 23C in Wales (Hawarden) and 21.6C in Northern Ireland (Ballywatticock).
There will also be little relief from the warm weather overnight, particularly in south-east England where some face a so-called tropical night - when temperatures stay above 20C.
Crowds returned to the coast on Sunday as the hot weather continued, with Dorset Council urging people to avoid Lulworth and Durdle Door by midday due to large numbers in the area.
Meanwhile, a woman has died following a collision between a water bike and a boat off Anglesey, in Wales.
Mr Hackwell added: “We’re heading into a period of more good weather so we want to remind you to check and double check tide times as even the most experienced swimmer or keen watersports enthusiast can get caught out by currents and tides.”
He urged people to plan their days out, “always exercise caution” and to make sure they have a way of contacting the coastguard if they get into trouble.
The coastguard co-ordinated search and rescue responses to a wide range of incidents on Saturday, including people being cut off by the tide and children swept out to sea on inflatables.
In total, the service responded to 186 emergency 999 calls, rescued 146 people and assisted a further 371.
Saturday’s incident count represents a “significant” 145% increase compared to the average number of call-outs recorded throughout August 2019, the coastguard said in a statement.
The hot weather and sunshine is set to continue throughout Sunday, according to the Met Office.
Met Office meteorologist Craig Snell said temperatures across England and Wales are expected to reach the high 20cs and low 30Cs on Sunday, while parts of Scotland and Northern Ireland may hit 24C.
However, thunderstorms are forecast for next week.
Yellow thunderstorm warnings have been issued for all parts of the UK for Monday through to Wednesday, with the Met Office stating “some places are likely to see severe thunderstorms early next week - but there is significant uncertainty in location and timing”.
Another yellow warning for thunderstorms has also been issued for England and Wales on Thursday.
Dan Harris, Met Office deputy chief meteorologist, said some places are likely to be hit with up to 80mm of rain in just a few hours.
Saturday saw crowds of people head to packed out beaches along the coast for the second day in a row.
Thanet District Council said Ramsgate Main Sands beach in Kent was “extremely busy”, with high tide likely to make social distancing difficult.
Blackpool Police also reported its beaches being busy and said it had a “larger than usual” number of children going missing.
In Norfolk, police recovered a body from a lake at Bawsey Country Park near King’s Lynn, following reports of a man getting into difficulty in the water.
South East Water urged its customers to put away their hose pipes, garden sprinklers and garden water toys, saying a spike in demand had left some people with low or no water.
Friday saw the hottest August day in 17 years, with the mercury hitting 36.4C at London’s Heathrow Airport and Kew Gardens.