Not necessarily.
From OSHA:
1910.147 (Lockout/Tagout) Standard does not apply to:
1910.147(a)(2)(iii)(A)
Work on cord and plug connected electric equipment for which exposure to the hazards of unexpected energization or start up of the equipment is controlled by the unplugging of the equipment from the energy source and by the plug being under the exclusive control of the employee performing the servicing or maintenance.
If you can't see the plug from where you are working you can always cut it off and take it with you - then you will have exclusive control of it:grin: