Official temperature readings collected by meteorologists come from thermometers shielded from the direct rays of the sun. That, after all, is the more accurate measure of air temperature at a given time.
In the Shade
A thermometer in the shade (of a tree or specially constructed weather shelter) measures the ambient air temperature.
In the Sun
But the same instrument placed in full sun heats up because of the solar radiation and therefore is not reflecting the actual temperature of the air itself. It may suggest a temperature far higher than one in the shade would. The degree to which it heats depends on its colour and material.
Feeling the Heat
This simple phenomenon is familiar to anyone on a hot, sunny day. Away from shade, you'll feel the full force of the sun and you'll absorb radiation through your clothes and skin. You'll feel notably cooler beneath a friendly tree canopy.
The shade of a tree keeps the underlying soil cooler than that exposed to full sun for the same reasons.
Plenty of animals, from insects and rodents to large mammals, beat intense heat and radiation by seeking shade.