Mars has such thin air that around noon near the equator, sunlit ground beneath your boots could reach 24 degrees Celsius while the air around your head remained below freezing

By Lachlan Brown – SpaceDaily

Imagine placing two thermometers on Mars at noon. One lies flat against dark, sunlit soil near the equator. The other hangs roughly at the height of a standing person’s head.

The lower thermometer could read 24 degrees Celsius, a mild spring day by Earth standards. The upper one could remain at or below freezing. Nothing separates them except about two metres of the thinnest lower atmosphere any person in a spacesuit is likely to encounter.