Well, Ajax969, that is a scarry situation .....
Maybe the electric PS motor is overheating; since it's inside the cabin, do you run with your A/C ON ..... ??
Maybe the PS ECU (or whatever is controlling it) is defective ... ??
Maybe the PS motor itself is defective .... ??
If it were me, I'd take it in to be fixed ASAP ...... even if I had to rent a car on my own $ for a week.
humfrz