If the mercury heads north of 70F in Britain, the nation tends to go 'summer crazy' and breaks out the budgie smugglers, sandals and shorts.

But spare a thought for residents in the city of Bandar Mahshahr, south-west Iran, where 'hot' has taken on a whole new meaning.

Today, it reached a super-sweltering 165F (74C) on the heat index (or 'feel-like' temperature), taking into account humidity - making it one of the highest temperatures ever recorded.

Bandar Mahshahr's air temperature registered 115F (46C) coupled with a dew point temperature of 90F (32C) at 4.30pm local time.

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Spare a thought for the residents of Bandar Mahshahr (above) in south-west Iran, where it reached a super-sweltering 165F (74C) on the heat index (or 'feel-like' temperature), taking into account humidity. This makes it one of the highest temperatures ever recorded

The heat index combines the air temperature with the relative humidity in an attempt to determine a human-perceived equivalent temperature - or how hot it actually feels

'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,' said AccuWeather meteorologist Anthony Sagliani.

The city, which has a population of more than 200,000, is the capital of Iran's Mahshahr County in the Khuzestan Province.

Residents had to endure a similarly stifling heat yesterday too, as the heat index climbed to 159f (70C) - and the forecast for the next few days gives little hope of respite.

The extreme weather has been triggered by a high pressure ridge - or 'heat dome' - over not just the Persian Gulf but the Middle East generally.

The highest known heat index ever attained was 178F (81C) in Dhahran, Saudi Arabia on July 8, 2003.

WHAT IS HEAT INDEX? The heat index combines the air temperature with the relative humidity in an attempt to determine a human-perceived equivalent temperature - or how hot it actually feels. For example, very high levels of humidity can make a 90 degree temperature feel like it's well over 100. Usually, the body cools itself by perspiring, which in turn evaporates and carries heat away from the body. However, when the relative humidity is high, the evaporation rate can be significantly reduced - and this process is compromised. As a result, the body has a harder time removing heat from itself, which makes it feel hotter than it actually is. Source: WeatherWorks Advertisement

And neighbouring countries are feeling the strain as well.

In Iraq yesterday, authorities declared a mandatory four-day holiday, to begin with immediate effect.

The government has urged residents to stay out of the sun and drink plenty of water.

But chronic electricity and water cuts in Iraq and other conflict-ridden countries make heatwaves like the present one even more unbearable - particularly for the more than 14 million people displaced by violence across the region.

In the southern Iraqi city of Basra earlier this month, protesters clashed with police as they demonstrated for better power services, leaving one person dead.

Unlike other countries in the region, Iraq lacks beaches, and travel restrictions make it difficult for people to escape the sweltering heat, leaving many - even those fortunate enough to live in their homes - with limited options for cooling off.

Some swim in rivers and irrigation canals, while others spend these days in air-conditioned shopping malls.

To the south, in the similarly sweltering Gulf, residents cranked up their air conditioners, and elsewhere in the Middle East, those who could headed to the beach to escape Thursday's soaring temperatures, high even by the standards of the region.

It is not uncommon for well-off Gulf citizens to decamp with their luxury cars and servants to cooler spots such as Britain or Switzerland as temperatures rise.

The extreme weather has been triggered by a high pressure ridge - or 'heat dome' - over the Middle East

Saudi Arabia's King Salman, joined by a delegation numbering in the hundreds, is currently cooling off in the south of France.

Several Gulf states, including the United Arab Emirates, Qatar and Saudi Arabia, mandate midday breaks when temperatures are at their highest for low-paid migrant labourers during the summer months.

But that only provides some relief as many still spend long hours working in the heat and travel to job sites on buses without air conditioning.

A Filipino migrant rights activist collapsed and later died of apparent heat stroke during a visit to his country's consulate in Dubai this week.

One of the hottest spots in the Gulf was Kuwait City, where Thursday temperatures were expected to reach 118F (48C).