Most gas and electric stoves nowadays come with an automatic stove shutoff, a motion sensor, and a timer. Modern units will allow you to set the number of minutes you intend to leave your food cooking on the stove unattended. Therefore, once the stove is automatically shut down after the expiry of the time that you set, you will have to manually turn it back on and just walk into the room to get it working again. The best units typically come with an automatic feature that will shut off the stove several minutes after the last person leaves the kitchen. These will typically shut off the stove after much less time as compared to manual timers. The feature will also record automatic shutoffs over time, so you track the memory changes of the elderly person over time.