Must have timer & keep away from flammable materials.
Never leave unattended or use when sleeping.
Plug directly into wall, never with an extension cord.
There have been numerous incidences of toasters ovens either catching fire or nearly so at Hopkins.
When the fire sprinklers go off in one room, they go off in the entire building.
As you can imagine, the water damage to all the electronics and papers in a building is nearly as bad as a fire itself.
Only the building survives in other words.
Toaster ovens are high amperage appliances and MUST be plugged directly into a wall outlet. They have short cords for a reason. If plugged into an extension cord, this cord will draw too much current and is in danger of starting a fire itself.
Toaster ovens produce a lot of heat, that is their purpose. Having anything else near them can catch that item on fire. This includes the wall itself. NEVER place anything on top of a toaster oven.
As they produce a lot of heat and people generally put flammable material into them (yes toast will catch fire if left in long enough). ALWAYS get a toaster oven with a timer. Then when you forget or get distracted, your item will not stay on HOT long enough to catch fire and set your kitchen area on fire too.