Electricians may position the outlet in an upside-down position so that you can quickly identify the switch-controlled receptacle. Since it stands out visually to most people right away – it provides convenience to the occupants to easily remember which outlet is switch controlled.

Do outlets have to be installed upside down?

The electrical code allows outlets to be installed with the ground plug hole facing up, down or sideways. It's up to you, there is no standard electric outlet orientation. So that means there really is no such thing as upside down outlets.

Why are receptacles upside down in hospitals?

Because if a cord or wire were to fall down on a partially plugged in right-side up outlet you would short out between the hot and the neutral. When the outlet is "upside down" in the above situation the wire would touch ground first.