"Consider that an ordinary laser pointer, powered by small flashlight batteries, generates peak temperatures of about 10^11 Kelvin. Yet you can shine it on your hand and not feel any warmth! This can happen because temperature represents the distribution of energy across physical states, and the fewer the states the higher the peak temperature, even at low energies.
The laser distributes a small amount of energy across very few states, which allows the temperature peak to get very large, despite not being perceptible by touch. Lasers are idealized in thermodynamics as having infinite temperature because ideally the laser radiation would have all of its energy in one quantum state."
How do you think Essex is defining temperature? Does it have much to do with a temperature measured in the atmosphere? If you are an expert in non-equilibrium thermodynamics, you may have a clue. For extra credit, why is this definition of what useful, and can you think of an interesting counter-example. The answer can be googled.
As for me, I have papers to mark.