Is there a way to stop sites from timing out?

My company requires me to log in to their secure website to retrieve email, enter time, etc. I am in a small, secure facility in a secure area. After about an hour of inactivity, the websites time out and I have to go through the process of logging back in, which includes using a triple-A token. Is there a firefox extension or other way to have my open browser periodically visit each site in the background while I continue to use my computer for other work? It's really annoying to constantly be having to log back in.