2 weeks notice

Jennifer • Boy mom 👦🏻🧑🏻‍🦲with three little 👼🏻👼🏻👼🏻

My husband works for an employer that is honestly horrible. He is currently looking for a new job. What makes me nervous is when he gives his 2 weeks notice that they just fire him on the spot. I read that they can do it because it’s “at will” but does that mean he has to give it? They do have an history of just firing after 2 weeks so I want to make sure we covered.