There isn't a single, universally-located "emergency cut-off switch" in the way some industrial machinery might have. Kia Sportages, and most modern cars, don't have such a switch readily accessible to the driver or passengers. The closest equivalent would be the main battery disconnect (which requires tools to access) or disconnecting the negative terminal of the battery itself (again, requires tools and is not meant for quick emergency use).
If you're experiencing a dangerous situation (fire, serious electrical issue), your best course of action is to:
* Evacuate the vehicle immediately. This is your top priority.
* Call emergency services.
Disconnecting the battery is a more involved process, generally located under the hood and requires some mechanical aptitude. It shouldn't be attempted unless you are trained and it's a genuinely safe situation to do so.