Ideally IMO you'd want a system with safeties in place. Like acceptable temperature ranges or durations for the oven to be on to avoid situations where the software misinterprets a command in a dangerous way.
Something like this:
User: Set temperature to 19 degrees. (Yeah it's on the cold side even for Celsius, but not a crazy amount as room temperature is around 22 degrees)
Assistant: Setting temperature to 90 degrees. (Deadly in Celsius... Water boils at around 100 degrees, depending on pressure)
Assistant: 90 degrees is outside of the safe range defined by your configuration. Intrusion suspected. Deploying sentry guns.