Where is the hottest place in the world?
There are a couple ways to look at answering this question: what place in the world has the highest temperature ever measured, or what place in the world has the highest average temperature annually. Really, to be the hottest place in the world, you would need to have the highest average temperature annually. This takes all four seasons of the year into account.
Just out of curiosity, where in fact was the highest temperature on Earth recorded?
On September 13, 1922, the high temperature for the day was recorded at 57.8°C (136°F) in the city of Al 'Aziziyah, Libya. To date, this is the highest temperature ever measured (in recorded history) on Earth. There is, however, some doubt to how accurate that reading actually was. The weather station, initially located in Al 'Aziziyah town, had been moved to a hilltop fort from 1919 to 1928. It was was set up there on black tarmac. This scenario would have presumably made the air there artificially hotter during those years due to the black tarmac absorbing more sunlight. Also, not long before the September 13, 1922 reading, the weather station's usual maximum thermometer had been damaged. The record reading was taken from a replacement maximum-minimum thermometer that was an uncalibrated and cheaper type of thermometer.
Keep in mind that 57.8°C is the highest measured temperature in recorded history, but higher temperatures have occurred at different times during the 4.55 billion years of Earth's existence.
The actual hottest place in the world is Dallol, Ethiopia!
Dallol currently holds the record for the hottest inhabited place on the planet. This record was measured between the years 1960 and 1966. During that span, the average annual temperature in Dallol was a very high 34°C (94°F). Even still, the temperature there regularly climbs past 115 degrees Fahrenheit.
Formerly a village, today Dallol is now nothing more than a mining ghost town and it is one of the most remote places on Earth. There are absolutely no roads and the only transport service provided is by camel caravans. The nearby volcano, numerous craters and volcanic lakes make for a colorful and attractive destination for brave travelers and tourists alike.
(Sulfur, salt, and other minerals color the crater of the Dallol volcano - http://photography.nationalgeographic.com/photography/enlarge/dallol-minerals-photography.html)