The UK's mini-heatwave saw the hottest day of the year so far yesterday, with even warmer temperatures expected in London and the south today.

Much of the country basked in sunshine with the mercury reaching 30C in London's Kew Gardens and St James's Park.

Thermometers are expected to climb to 34C (93.2F) today, prompting Government officials to issue health warnings.

With the warm weather expected to last until the end of Wednesday, Public Health England (PHE) is advising a common-sense approach to dealing with the heatwave.

Keep hydrated

People are urged to drink plenty of water and avoid dehydrating alcoholic and caffeinated drinks, close curtains to keeps rooms cool, open windows and avoid people and animals being left in closed, parked vehicles that can get extremely hot.

Stay cool

There are also warnings to stay out of the sun between 11am and 3pm, avoid physical exertion at the hottest times of the day and stay in the shade - and to put on a hat and wear sunscreen.

Dr Angie Bone, PHE's head of extreme events, said: "For some people - such as older people, those with underlying health conditions and those with young children - summer heat can bring real health risks.

"This summer we're urging people to keep an eye on those at-risk and if you're able, offer help to stay cool and hydrated."

News Shopper: Temperatures are set to soar even further as Britain faces a summer heatwave

Watch out for heat stroke

St John Ambulance has also issued advice, urging people to be aware of headaches, dizziness and cramp which can be signs of heat exhaustion and heat stroke.

Clive James, from the charity, said: "Heat exhaustion and heat stroke are the most serious problems that can develop when the mercury soars, so it's essential that people can spot the signs - such as headache and dizziness - and get them somewhere cool and rehydrated as soon as possible."

Babies, young children and the elderly

Public Health England (PHE) is urging people to look out for elderly relatives and friends who may be susceptible to the high temperatures - and to take extra care of young children, babies and those with heath issues.

Pollen levels will be high over the country for the next few days, causing havoc for hay fever sufferers - and there may be another restless night on Tuesday as temperatures reach 22C (71.6F) overnight.

The hot weather has been caused by a warm plume of air that has worked its way northwards from Spain, the Met Office said.

Forecaster Grahame Madge said temperatures from London to the West Midlands could reach 34C (93.2F) on Tuesday, before thunderstorms bring up to 50mm of rain and the possibility of flash-flooding - with a weather warning for everywhere north of a line stretching from Bristol to The Wash.

He said: "The July temperature record was set on July 1 last year with 36.7C (98.1F) at Heathrow.

"We are not suggesting that temperature will be exceeded by anything we have got this week, but the temperatures that we do have will be the warmest we have seen in the last 12 months."

Wednesday will see highs reaching the low 30Cs, but by Thursday fresher conditions from the Atlantic will bring temperatures down to the more comfortable mid-20Cs, reaching around 22C (71.6F) to 24C (75.2F) by Friday and Saturday.