The U.S. Open is underway.
Look to see some towels draped over the head.
It's not just an escape from the heat of the sun.
It's an escape from the heat of the game.
In yoga, this sort of sensory withdrawal is called pratyāhāra.
You cover the eyes, nose, ears and mouth - withdrawing the senses from any external objects.
Pratyāhāra literally means 'gathering toward oneself.'
It's a centering practice.
To draw you toward the calm within.
With the TV cameras rolling, and the line judge waiting, there's not a lot of room to escape.
But players seemed to have found a simple solution.
And in doing so, they have tapped into an ancient practice.