When you imagine temperatures of over 110F (43C), you picture blistering sunshine and the need to find shade, yet for a good part of our drive across the desert from the Grand Canyon to Joshua Tree, the temperature gauge is up there above that number yet the skies are consistently overcast. It even rains a couple of times. When we step out of the car for a break, we are hit by a wall of heat incompatible with the cloudy skies above. Leaving the Interstate 140, we drive south west through some extraordinarily barren country, miles of dead straight road through open land. Once past the salt flats at Amboy…