I think that you mean the cord from the charger to the wall. That's where the higher voltage is present. It's not a problem at all. The cord is deliberately designed accordingly. If you care, the details are...
Wire size concerns are more related to current (amperage) than to voltage. The charger electronics controls the current from the charger to the device which indirectly controls the current from the wall to the charger.
By the way, the comment about your camera does not sound correct. I suspect that you may have misread the information. Is that information available as a link? I'd like to read it myself.