The city of Bandar Mahshahr, which lies adjacent to the Persian Gulf southwest Iran with a population of 110,000 people, experienced a heat index of 164 degrees Fahrenheit on Friday.

The rise in temperature follows the 109 degrees Fahrenheit (43 degrees Celsius) air temperature and a dew point of 90 degrees Fahrenheit (43 degrees Celsius), resulting in a heat index of 154 degrees Fahrenheit (67.8 degrees Celsius) that the city experienced on Thursday. Heat indexes refer to how hot the air feels, combining air temperature and relative humidity.

"In his book Extreme Weather, a weather historian says Dhahran, Saudi Arabia, also on the Persian Gulf, logged a heat index of around 155-160 degrees on July 8, 2003. Its air temperature was 108 degrees, with a dew point of 95," weather historian Christopher Burt said, according to Mashable.

"That was one of the most incredible temperature observations I have ever seen, and it is one of the most extreme readings ever in the world," Accuweather meteorologist Anthony Sagliani said in a statement, U.S.A. Today reported.

"A strong ridge of high pressure has persisted over the Middle East through much of July, resulting in the extreme heat wave in what many would consider one of the hottest places in the world," Sagliani added.

Though unofficial, the rise in Iran's heat index is to challenge the reported highest heat index ever recorded. Said record took place in July 2003 in Dhahran, Saudi Arabia at 178 degrees Fahrenheit, or 81 degrees Celsius.

The government has warned the public of the dangers of living in extreme heat on a long duration, urging them to drink plenty of water and stay out of the sun. However, in cities affected by war, particularly for the more than 14 million people displaced by violence, water and electricity cuts make this dilemma unbearable for many, according to The Washington Post.