A city in Iran felt like it was 68C (154F) on Thursday after a freak combination of extreme humidity and temperatures created conditions which are believed to be some of the "most extreme ever observed".
Residents of Bandar Mahshahr, a city near the mouth of the Persian Gulf, were subjected to the stifling heat when the temperature hit 43C (109F), and the dew point reached 32C (90F).
Anthony Sagliani, a weather risk analyst and meteorologist for, tweeted his shock at the freak weather conditions.
Answering questions on Twitter about the phenomenon, Sagliani explained the 68C figure was "apparent temperature when air temperature is combined with humidity. (68 degrees C or 154 degrees F)".
He added: "It is possible to survive, but you certainly won't be able to endure it for more than a few minutes without water and shade."
Bandar Mahshahr is the capital of Iran’s Mahshahr County in the Khuzestan Province and is home to just more than 200,000 inhabitants.
The hottest day on earth was recorded in July 1913, when Furnace Creek in Death Valley, California, hit 57C.
Bandar Mahshahr
The highest heat index ever recorded is between 68.3C and 71.1C, felt in Dharhan, Saudi Arabia on July 8, 2003, according to The Vane.
As History in the Headlines reports: "Seven years after Death Valley’s record-breaking day, South America experienced its hottest day when the mercury reached 120.4 degrees Fahrenheit in Villa de María, Argentina.
"In 1931, the south Tunisian town of Kebii saw temperatures reach 131 degrees Fahrenheit, making it the hottest day on the African continent.
"Ownership of Europe’s hottest day is under debate, with most scientists rejecting Catenanuova, Italy’s 1999 claim of 119.3 degrees in favour of the 118.4-degree day residents of Athens, Greece endured in July 1977."