However, according to experts, the high temperature is not a sufficient measure of whether living is possible in a certain city. The exact measure is heat combined with humidity. For this reason, life in the Middle East is more difficult than in Europe - even if the temperatures are the same.

Abdan in Iran recorded a record high of 53 degrees Celsius on August 5. But the heat is not accompanied by high humidity. If, in addition to the temperature, there was also high humidity, living in the area would become much more difficult, even impossible. This is because it is difficult for our body to cool itself when there is humidity compared to dry weather.

The combination of heat and humidity is known as heat load, and is determined as a combination of the temperature and the relative humidity. The calculation is an average of the dry bulb temperature (dry bulb temperature) and the wet bulb temperature (wet bulb temperature).

The dry bulb temperature is the temperature measured by a thermometer, under conditions without radiation and without moisture. The wet bulb temperature is measured with a thermometer covered with a cloth soaked in water and takes into account both heat and humidity.

The Middle East in particular is exposed to an increase in the wet bulb temperature. "The region is already hot and humid. Therefore, the increase in global temperature may make the region dangerous for human health," Tapio Schneider, a professor of climate science and engineering at the California Institute of Technology, told CNN.

The Persian Gulf is one of the few places in the world that recorded wet bulb temperatures higher than the threshold at which a human can survive - 53 degrees Celsius. Since 2005, there have been nine cases where the temperature rose to such a level.

This means that at a temperature of 35 degrees in a humid phase, the human body is unable to cool itself to the temperature at which the body functions under normal conditions. "This is the threshold above which humans are unable to survive and will die within a few hours," Schneider said.

A moist bulb temperature below 53 degrees is also not ideal. "Humans experience heat stress even at a lower humid bulb temperature. How they can survive such conditions depends on physical fitness and age among other things," said Schneider.

The countries of the Persian Gulf defend against the heat, using energy-saving air conditioning, but other countries in the region are not so rich, and therefore less protected. In Iraq, for example, workers in the city of Basra were asked to stay at home due to high temperatures earlier this month. However, households only receive electricity for ten hours a day from the national grid.

Only those who are able buy a generator to generate electricity for the remaining hours.