There little heat retained in the warm thermosphere because:
The pressure is too low
Step-by-step explanation:
The thermosphere is the layer of Earth's atmosphere that however includes substantial molecules of complex gases. It transpires below the outermost layer, the exosphere. The thermosphere is the layer of Earth's atmosphere that still includes abundant molecules of complex gases. It occurs below the external layer, the exosphere. Heat and PressureThe remarkably low pressure of the thermosphere also adds to its high temperature.