Thousands of Britons are flocking to beaches and beauty spots for what is set to be the hottest Bank Holiday ever.With temperatures predicted to soar to a 'historic' 35C today, the UK Health Security Agency (UKHSA) and NHS have warned Brits to keep out of the sun - especially at the hottest time of the day, between 11am and 3pm.But this has not put sunseekers off, with thousands packing out Bournemouth Beach and others enjoying early morning swims at Hyde Park's Serpentine in London as they enjoy the final day of a scorching long weekend. It comes after a man died on a packed beach in Hastings, East Sussex, and a 15-year-old boy drowned in Swanholme Lakes, in Lincoln, on Sunday, the hottest day of the year so far.Amber and yellow health alerts remain in place across England, as temperatures continue to soar on what the Met Office has described as an 'unprecedented' heatwave for this time of year.For those areas under the alerts, the UKHSA has warned of 'significant impacts' across health and social care services - including a "a rise in deaths, particularly among those aged 65 and over or with health conditions". Parts of the country were as hot as the Mediterranean on Sunday, with the UK enjoying its hottest May day for at least 79 years with a high of 32.3C at Kew Gardens in south-west London. But the Met Office has declared that the mercury is set to climb to a searing 35C today, which would make it Britain's hottest bank holiday ever - including August. The current May record is 32.8C.Tom Morgan, a Met Office meteorologist, said: 'We rarely see temperatures above 35C, even in the summer months, so to see temperatures getting close to 35C in May is, as I say, pretty historic.'Brits were seen lounging on Bournemouth beach in Dorset early on Bank Holiday Monday Sunseekers flock to Bournemouth Beach as temperatures reach 'historic' highsHe said overnight temperatures could also lead to records being broken, making it 'uncomfortable for sleeping'. Overnight, the Met Office said it had provisionally recorded the UK's highest daily minimum temperature for May on record. Temperatures did not fall below 19.4C at Kenley Airfield, Greater London, overnight, provisionally breaking the previous May record of 18.9C set back in 1944. Wales and Northern Ireland also reached 2026 record temperatures of 27.4C in Cardiff and 23.4C in Armagh on Sunday.Scotland saw highs of 23.5C in Edinburgh on Sunday, just below the current record of 23.6C recorded in Aboyne on May 1. The Met Office said eight regions officially entered heatwave conditions on Sunday after three days at or above the temperature threshold. They were Heathrow in Greater London, Benson in Oxfordshire, Brooms Barn in Suffolk, High Beech in Essex, Kew Gardens in London, Northolt in London, Santon Downham in Suffolk and Writtle in Essex.Sunseekers and families were seen packing out beaches and parks across the country.Thousands were pictured luxuriating in the heat at Brighton Beach, Bournemouth, Lyme Regis and Devon.While many more swarmed local lidos and nearby rivers over the three-day weekend. Meanwhile revellers did not let the heat stop them partying at Bank Holiday festivals over the weekend - including the BBC Radio 1's Big Weekend at Herrington Country Park, Sunderland, as well as star-studded events in Brockwell Park, south London.However, there were also scenes of chaos on Saturday as youths were pictured inhaling so-called 'hippy crack' on Bournemouth beach while a girl was carried away on a stretcher.Later on in the afternoon, six officers went onto the beach and apprehended a young man for unknown reasons before escorting him away. He apparently resisted arrest all the way to the promenade before being placed in a police van as bystanders watched on.Police also had to intervene when a group of girls brawled near the Red Arrows simulator. One of the girls appeared to have her hands around another female's neck before the skirmish was diffused.Elsewhere, in Lincoln, the body of 15-year-old Declan Sawyer was recovered Swanholme Lakes after he disappeared while swimming with a group of friends during the heatwave.Authorities have warned about the dangers of swimming in reservoirs and lakes over the weekend. A woman braves the searing temperatures for a morning run in Wimbledon Common People enjoy the hot weather on Bournemouth Beach Families were seen going for dips in the sea for the scorching Bank Holiday Monday A swimmer cools off in the sky pool in Nine Elms, south London Animal lovers take part in Alpaca yoga at Hope Farm, Dorset A man tells his dog to go fetch at water fountains in Battersea Park, south west London Londoners flocked to Parliament Hill lido to enjoy the scorching heatwave over the weekend Tourists enjoy a river cruise along the Thames in London A man floats down the River Great Stour in FordwichAlthough Monday is set to be hot for many parts of England, north-west Scotland will be breezier and damper with thicker clouds.Saturday was the first time this year that the UK had passed 30C and Sunday saw the hottest recorded May temperature since 1947.The UKHSA issued its first amber health alert of 2026 on Friday, warning that there is a risk of a significant impact across health and social care services. The alert will remain in place until Wednesday.The heat is considered to be dangerous for some vulnerable groups including older adults as their bodies struggle to regulate temperature.Dr Anya Gopfert, Consultant in Health Protection at UKHSA, said: We know that even moderate heat can lead to serious health problems, especially for older people and those with certain health conditions, so it’s important that everyone takes simple precautions while enjoying the warm weather over the coming days.'If you have friends, family or neighbours who are more vulnerable, it is important to check in on them and ensure they are aware of the forecasts and are following the necessary advice.'Age UK recommends staying inside during the hottest hours of the day, between 11am and 3pm, and having regular cold baths or showers.Age UK charity director Caroline Abrahams said: 'We can all help older people stay safe during periods of hot weather by checking in on older relatives, friends and neighbours to see if they need anything or are struggling with the heat.'Offering to pick up shopping or medication, or even lending a fan, can make a real difference.'