London and south-east England can expect highs of 29C and clear skies on Sunday, after Friday saw parts of the country warmer than Los Angeles and Santorini. And the heatwave will continue into next week, with temperatures topping 33C on Tuesday, potentially making it the hottest day of the year so far. With many families expected to head to beaches and parks to enjoy the warm weather, Sheffield Children’s NHS Foundation Trust is advising parents not to let children run around in the sun and ensure they stay hydrated by drinking water “little and often”. The trust tweeted: “Don’t leave your children in the sun for long periods – and never leave them in a car on a hot day. It is important to rest in the shade and find cool places. “The first sign that a child is overheating is when they whine or complain of a headache. If this happens, place them in a shady place that is as cool as possible. Take off what clothes you can, give them water to drink and let them rest. “Following these simple precautions means you and your children can enjoy the sun safely.” The British Red Cross has also issued advice on how to spot the signs of heat exhaustion and heat stroke. The agency reminded people to “keep cool, stay hydrated and call 999 if their condition worsens”. The UK Health Safety Authority (UKHSA) and the Met Office have issued a level 3 heat health alert for London, the east of England and the south east from 9am on Monday until 9am on Friday. A level two alert will also be in place for the South West, East Midlands, West Midlands, North West, Yorkshire and the Humber. People enjoying the warm weather at Southsea Beach in Hampshire on Saturday (Andrew Matthews/PA) Dr Agostinho Sousa, Head of Extreme Events and Health Protection at UKHSA, urged people to look out for vulnerable family, friends and neighbors during the heatwave. Temperatures soared across the country on Friday, with the mercury reaching 28.5C in London’s St James’s Park. This year’s record high currently stands at 32.7C, recorded at Heathrow on June 17.