That is a real worry!
The UNO is a particularly inconvenient board format. The Nano is the "workhorse" version of the UNO, used for serious designs that have to do something rather than just play. It uses the same processor and thus code, just a different package, and also implements the final two, analog-only input ports.
It is far more practical than the UNO, usually comes without the pins soldered so you can solder the pins in to mount on a "solderless breadboard", or a terminal adaptor or as a daughter-board to your own custom PCB, or you can solder wires directly to the Nano PCB.
The UNO on the other hand comes fitted with sockets which limit you to flying leads or a matching "shield" so unless there is a shield which does exactly what you want (or you use a "prototyping shield" within its limitations), construction becomes messy.
One clear problem with the UNO which is primarily designed to mount "shields", is the means to connect to the sockets. Simply sticking wires in them is clearly unreliable. The proper way is to insert pin headers into the sockets, and solder to the pin headers. It is far more difficult to dislodge a whole multi-pin header than an individual wire.