When your bathroom outlets suddenly short when, say, you’re blow-drying your hair or shaving your beard, you may be tempted to call your electrician. Before you do, check your GFCI outlets.

GFCI stands for “ground-fault circuit interpreter.” These outlets were introduced in the early 1960s to prevent as many as 800 fatal shocks each year. These crucial safety devices, which, by code, must be on all outlets within six feet of a water source, cut power if a circuit begins to lose amperage. Resetting the outlet is often as simple as hitting the “reset” button on the outlet itself.

The thing your electrician wants you to know is that GFCIs protect everything downstream. You may notice that seemingly unrelated outlets and switches are off, too. If that’s the case, your GFCI may be installed on the breaker box itself, in which case, the fix entails resetting the circuit at the box.