What to do when not deployed?

This is for those who work in emergency response where you have the chance to be deployed often and possible short periods of time. I have just now started to work in emergency response, where I also have a normal job, but have not yet been deployed yet since I only just started with a company.

The problem I can see in my future is that I get deployed on a project that could be over a month long, and im not sure how my other job is going to handle me being gone for so long/short notice. However, since its emergency response, I cant quite rely on it to be my main source of income since it can be quite inconsistent.

I plan on eventually going full time with this emergency response company since thats what im interested in, but I need a reliable source of income until that happens.

So my question is, what do you guys do when you have long spells of non deployments?