SWELTERING weather is set to sweep across the country, bringing sticky conditions, high UV levels and possibly the hottest day of the year.

Temperatures are expected to reach the low thirties - as hot air from the continent warms up the country.

In July thermometers reached 33.5C at Brize Norton in Oxfordshire and the Met Office said the mercury could reach those highs again if conditions are right.

"The warmest day is looking to be Tuesday where we'll probably see temperatures in the low thirties around to the north of London, the Midlands and East Anglia," said forecaster Emma Sharples.

While temperatures are not expected to reach the mid-thirties, it would be "close-run thing" whether Tuesday would be the hottest day so far this year, she said.

Monday will see highs of 28C in the south, with temperatures this weekend staying in the mid-twenties. Scotland could also experience temperatures in the high twenties, the Met Office said.

Sticky conditions will make it difficult to sleep, particularly in urban areas and UV levels are predicted to be high.

But the hot weather is not set to last long as thunderstorms will creep in on Tuesday night into Wednesday.

Ms Sharples said: "By the time we get to Thursday we'll be back into much fresher conditions again, temperatures down to around average in the high teens and low twenties with a typical mix of summer weather which we're more used to in the UK."

The forecaster also dismissed suggestions that a "Spanish Plume" would bring hot weather to the country for the next fortnight.

"A Spanish Plume refers to how we break down the spell of warm sunny weather and the act of thunderstorms happening - so it's a title of an event to define a set of characteristics that set off thunderstorms," she said.

"It's not the Spanish Plume which produces hot weather really, although they tend to come in tandem."

The mini-heatwave comes as research by the Teenage Cancer Trust found that young people are careless when applying sunscreen and regularly burn in the sun.

The charity found that 16 per cent of young people have been burnt more than 10 times in their life - putting them at a high risk of developing skin cancer.

Susie Rice, head of education and awareness programme for the trust, said it is important that young people know how to protect themselves as skin cancer is on the rise.

"It's so worrying to see that young people are getting bunt frequently, as we know that repeated burning can cause problems over time," she said.

"We want young people to really think about those bits they normally miss when putting on their sunscreen this summer."

The research suggested that a third of 13 to 24-year-olds suffer burned necks because they forget to apply sunscreen, while the same number get burned backs.

And NHS England South is advising people to wear a hat, sunscreen and sunglasses as part of its Cover Up, Mate campaign.

Nigel Acheson, NHS England South medical director, said: “We all like to joke about the Great British Summer, but as July’s mini heatwave showed, just a few hours of unexpected hot sun can be really intense.

“The dangers are all too clear, not only getting burned or sunstroke but also the added risk of developing skin cancer later in life.

“Put simply, Cover Up, Mate with hat, sunscreen and sunglasses to protect yourself and your family.”

Latest statistics from Cancer Research show that since the late 1970s, skin cancer incidence rates have seen a 360 per cent increase in Great Britain.

Figures from Public Health England show the south has seen a huge rise in incidence of and deaths from malignant melanoma in recent years, with

many areas across the south having higher rates of malignant melanoma than the national average.

Top sun safe tips include:

• Use plenty of least factor 15 sunscreen in the sun;

• Apply sunscreen to all exposed skin – don’t forget your neck and ears and your head if you have thinning or no hair;

• Wear sunglasses and a hat;

• Take particular care if have fair skin, moles or freckles, red or fair hair, or light-coloured eyes.

And pet owners are being warned that rocketing temperatures can be very harmful and even fatal in some cases.

Dr Huw Stacey, director of clinical services at Vets4Pets which has branches in Swindon, said: “The impending heatwave in the UK means pets will be at high risk of suffering from heatstroke, so owners need to take the necessary precautions to help keep their pets as cool as possible.

“Every year, pets suffer or even die when their owners make the mistake of leaving them inside a parked car, even if it is just for a few minutes.

“Whilst many owners will already know to never leave their pets in a car on a warm day, not everyone is aware that conservatories and caravans can be equally as dangerous.

“Cars, conservatories and caravans all act as a sun trap, and even if it feels relatively mild outside, temperatures inside can soar between 38 and 50C degrees in minutes.

“Being subjected to these kinds of temperatures can not only lead to heatstroke, but can also cause fatal brain or organ damage. A mortality rate of 50 percent has been reported if temperatures reach 65C degrees, which can easily happen in a car or conservatory on a hot day.”

High temperatures can also make the asphalt on roads and pavements dangerous for pets, as it can reach an unbearable 60 degrees in 30-degree weather.

“Asphalt can become far too hot for pets’ sensitive paws and pads and can cause burns, blisters and permanent scarring after just one minute of contact,” said Dr Stacey.

“Keeping pets in shaded areas and walking dogs at cooler times of the day can help avoid burnt paws.

“Smaller pets, including rabbits, guinea pigs and hamsters, can also suffer from heatstroke if they are exposed to direct sunlight for extended periods of time.

“To help keep them cool, it is always best to move their cages or hutches into shaded areas of the garden or into a cool area of the house, garage or shed.

“Dehydration from excessive panting can be a contributor to heatstroke but can also cause serious problems on its own."