He gets anxious if there is no wireless connection in the hotel or if his cell phone has no signal in the mountains.
He fidgets if his phone has a low battery and quietly worries that things will not be right at the office during his absence.
Those are typical signs of «always on» stress induced by smartphone addiction.
For some people, the portable devices that connect have been a release from the restrictions of fixed office hours. The flexibility has given them more autonomy over their working life and allowed them to spend more time with their friends and families.