Why do toasters have a “ONE SLICE” slot?

Dear Cecil: I love to fix toasted tuna fish sandwiches, but sometimes a whole one is too much and I make one with only one slice of bread. Imagine my horror and shame recently upon realizing I’d toasted the single slice in the wrong slot of the toaster (the one not marked “ONE SLICE”)! I ate it anyway. What are the implications of using the wrong slot--jail, food poisoning? Why is there a “ONE SLICE” slot at all? Cliff F., Springfield, Virginia

Cecil replies:

Dear Cliff:

The “ONE SLICE” slot is where the toaster’s thermostat is. Use the other opening and you could wind up with under- or overcooked toast. If your toaster has an energy-saver feature, in which only the heating coils in the center and on one side warm up when you make one slice, things might come out half-baked.

Cecil Adams

Send questions to Cecil via cecil@straightdope.com.