My Mother is elderly and has dementia. She has a gas stove. Is there something that we can turn off the stove and keep it off until aide comes back the next day.

Here's a site

iguardfire.com

I agree with Sunnygirl - and I would add that you need to consider a higher level of care for mom if she's doing things like trying to cook on a gas stove by herself. She could get herself into all kinds of trouble when she's alone.

Some folks suggest taking the knobs off and hiding them. Make sure you don’t have pliers handy to turn with in case she thinks of that.

I might examine what other things that your mother might do that is unsafe after the aid leaves. Once, risky behavior starts, there is no way to know what kind of things she might do to harm herself, including, mistaking medications, eating non-food items, leaving the house, not being able to leave house in case of fire, letting in strangers, etc.

Two ways to do this. Turn off the gas valve or unplug the electrical cord. Modern gas stoves still need electricity for igniters and controls. Problem...Both are hard to get to, usually behind the stove.