How do you Accurately measure High temperatures in Hot climates ?

[heatseeker]

I'm curious about the Hottest spot on Earth in Average High, looks like Furnace Creek ( Death Valley ) and Basra, Iraq / Kuwait are near the top. 

Furnace Creek claims an Average July High of 47 C but the Sahara Desert might have hotter spots.

Another spot I'm curious about is Dallol, Ethiopia, apparently Hottest Average Highs measured over 12 months though some readings are from the 1960s.

What is the best way to measure High temperatures in a Hot climates ? 

Many sensors mounted on AWS towers are in Direct sunlight, the sensor enclosure isn't shaded even though its painted white.

Does direct sunlight on the sensor enclosure significantly inflate readings ?

This solar insolation must be a significant factor with a high sun and temps over 35 C.

In a place like Dallol or Basra or even Death Valley, the Sun goes to or near Zenith so the solar radiation on the sensor enclosure must be a factor in daytime readings.

What are the engineering considerations here ?

Any opinions welcome.