Back in the days before central heating, when coal was the only way to heat your home, smog was part of the British climate a sometimes lethal mixture of fog, smoke and other pollutants.
Known as a pea-souper' because its colour and density was reminiscent of pea soup, the smog was so thick and choking it literally brought whole towns to a standstill.
London's famous pea-souper' of 1952 known as the Great Smog killed more than 4,000 people when it shrouded the capital, and 104 of those victims were from Croydon.
Many of the deaths were respiratory-related but the smog was also blamed for causing car accidents.
It is also believed people who were exposed to smog suffered health problems long into their lives.
According to newspaper reports at the time in Croydon, people were forced to abandon their cars in the middle of the road because they could not see where they were going.
Cinemas were forced to close because the atmosphere inside theatres was too thick to see the screens.
John Bishop, of Kenmore Road, Kenley, remembers his own experience of a pea-souper' as a 15 year old in 1941 and how he had to navigate his way home in the dense soot-filled fog.
John, now aged 79, had been to the Savoy cinema in Broad Green where he watched an evening show.
He said: "After the show I stood in the bright lights in the foyer and looked out towards the street.
"There was just a halo of light on the pavement in front of the cinema but a very thick fog had made the area all around invisible.
"I walked very carefully towards the kerb.
"Looking down I could not see my feet.
He added: "I walked out into the road until I reached the tramlines.
The dense fog seemed to blanket all sound.
"There was no traffic moving."
Knowing the tramlines would guide him back to Warwick Road, near where he lived, John turned left and carefully followed the lines.
"I recognised the Thornton Heath tram depot only because points turned left there and the Brigstock Road points turned right," added John.
"If a tram came up behind me it was clanging its bell and travelling only at walking pace so I could get to one side to let it pass."
When John judged he was nearing Warwick Road, he walked over to the left-hand pavement and felt his way along the hedge-lined house fronts until he could read the road sign up close.
He added: "I could not see either side of me and I had to walk down this road touching the hedges of the houses to keep in the right direction.
"I didn't want to walk into a lamppost.
"When I got home my clothes were dripping wet, my eyebrows were wet and my nose had this black smut all around it."
The Great Smog of 1952 prompted the Government to introduced the 1956 Clean Air Act which introduced smoke controlled areas and chimney heights.
Pea-soupers' have become a thing of the past.
This is partly due to central heating and pollution legislation that was brought in.