Firefighters are battling a raging wildfire just after record-breaking temperatures ignited infernos across the country.
A major incident has been declared at Hankley Common in Surrey as a large fire rages out of control, while similar incidents have also ben reported in Thamesmead, Hayes and Enfield.
Surrey Fire and Rescue has urged nearby residents to keep their windows closed and their pets inside until the blaze at the 560-hectare nature reserve is extinguished.
A spokesman confirmed they were called at around noon and 19 vehicles are in attendance.
He added: “We have declared a major incident at Hankley Common due to a large fire in the open.
“We have several fire engines in attendance. There is a great deal of smoke so please avoid the area, windows and doors should be closed if nearby and pets kept indoors.
“Please avoid the area to allow our crews to work. Stay out of the smoke and far away from the fire as it can travel quickly.
"We were called to the fire just after midday today & currently have 19 vehicles in attendance, including fire engines, specialist units and 4x4s. At least eight hectares are estimated to be affected."
Terrifying footage of the fire -the third in less than two weeks at the beauty spot - show the extent of the flames and smoke at the scene.
Some of the smoke has been reportedly seen on the runway of nearby Heathrow Airport.
Surrey Police added: "There is an increased presence of Police and the Fire Service at Hankley Common near Godalming due to a Fire.
"We are asking the public to avoid the area until further notice."
Resident Alan Johnson told Surrey Live he had been to visit a disabled friend in the area which was being evacuated.
He added: "It's an absolutely massive fire. I believe some army buildings in the area may have been subsumed by it, although I don't know.
"It must stretch for at least half a mile. There are myriad firefighters there but it's very difficult to get to because it's on a common, so the sort of vehicles that can get to it are quite small.
"I don't know how much water they can carry but I can't imagine it's very much."
London Fire Brigade later urged people to cancel all planned barbecues as they were responding to several incidents.
They tweeted: "London Fire Brigade is dealing with a number of weather related fires across the capital.
"We're tackling significant incidents in Enfield, Hayes and Thamesmead. Between midnight and 1700 we've attended more incidents than we would in a normal 24 hour period.
"Please help us prevent further fires by cancelling all planned BBQs, removing rubbish especially glass from grassland & disposing cigarettes correctly.
Hankley Common is a popular filming location and has appeared in two James Bond films - The World Is Not Enough and Skyfall - as well as 1917 and The King's Man.
One thankful resident said: "Stay safe crews. One awful one after another.
"Thank you all you do."
Another reported her pets were unimpressed to be kept inside.
She added: "We live by there and had to shut the doors and windows due smoke.
"Cats not happy they had to come in either."
Around 100 crews are at the scene of a serious fire in north London where dry grass in Enfield is alight for the second time in 24 hours.
A London Fire Brigade spokesperson said: "The fire produced smoke and ash which was blowing towards local properties and over the M25 between junctions 25 and 26.
"We asked residents to keep windows and doors closed whilst firefighters worked to bring the blaze under control.
"We’re urging people to take extra care and help us prevent fires on open land this summer.
"Make sure rubbish, especially glass, is safely thrown away and cigarettes are always properly disposed of.
"Grass will be tinder dry after periods of hot weather, so please don’t have barbecues in parks and public spaces."
Another blaze has also been reported in Thamesmead.