If you think you are going to get fired from your job, start to BCC your personal email on all communication with your managers

As soon as they fire you, you will lose access to all your work emails and it will be much harder to make a case if you are unjustly fired. BCCing those emails will help to ensure you cover your own butt and have evidence that you did nothing wrong. This could be helpful for unemployment, future jobs, or even a lawsuit.